BioLargo (BLGO) 10-Q14 Nov 232023 Q3 Quarterly reportFinancial data

Company Profile

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
Document And Entity Information - shares	Sep. 30, 2023	Nov. 10, 2023
Document Information [Line Items]
Entity Central Index Key	0000880242
Entity Registrant Name	BIOLARGO, INC.
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2023
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
Entity File Number	000-19709
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	65-0159115
Entity Address, Address Line One	14921 Chestnut St.
Entity Address, City or Town	Westminster
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92683
City Area Code	888
Local Phone Number	400-2863
Title of 12(b) Security	Common stock
Trading Symbol	BLGO
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		289,500,358

Consolidated Balance Sheets (Cu

Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 3,042,000	$ 1,851,000
Accounts receivable, net of allowance	1,453,000	1,064,000
Prepaid expenses and other current assets	74,000	120,000
Inventories, net of allowance	122,000	118,000
Total current assets	4,691,000	3,153,000
Property and equipment, net of depreciation	599,000	287,000
Other non-current assets	69,000	124,000
Investment in South Korean joint venture	15,000	33,000
Right of use, operating lease, net of amortization	777,000	867,000
Clyra Medical prepaid marketing	394,000	394,000
Total assets	6,545,000	4,858,000
Current liabilities:
Accounts payable and accrued expenses	889,000	940,000
Debt obligations	66,000	100,000
Deferred revenue	2,000	17,000
Lease liability	97,000	97,000
Customer deposits	122,000	184,000
Total current liabilities	1,740,000	1,576,000
Long-term liabilities:
Debt obligations, net of current	293,000	237,000
Lease liability, net of current	695,000	773,000
Total long-term liabilities	988,000	1,271,000
Total liabilities	2,728,000	2,847,000
COMMITMENTS AND CONTINGENCIES (Note 12)
STOCKHOLDERS’ EQUITY:
Preferred Series A, $0.00067 par value, 50,000,000 shares authorized, -0- shares issued and outstanding, at September 30, 2023 and December 31, 2022	0	0
Common stock, $0.00067 par value, 550,000,000 shares authorized, 288,626,570 and 278,462,706 shares issued at September 30, 2023 and December 31, 2022, respectively	193,000	186,000
Additional paid-in capital	153,406,000	148,435,000
Accumulated deficit	(146,369,000)	(143,594,000)
Accumulated other comprehensive loss	(161,000)	(149,000)
Total BioLargo Inc. and subsidiaries stockholders’ equity	7,069,000	4,878,000
Non-controlling interest	(3,252,000)	(2,867,000)
Total stockholders’ equity	3,817,000	2,011,000
Total liabilities and stockholders’ equity	6,545,000	4,858,000
Entities, Excluding Partially Owned Subsidiary [Member]
Current liabilities:
Accounts payable and accrued expenses	889,000	940,000
Partially Owned Subsidiary [Member]
Current liabilities:
Accounts payable and accrued expenses	330,000	238,000
Debt obligations	234,000	0
Long-term liabilities:
Debt obligations, net of current	$ 0	$ 261,000

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Convertible Preferred Stock, Par Value (in dollars per share)	$ 0.00067	$ 0.00067
Convertible Preferred Stock, Shares Authorized (in shares)	50,000,000	50,000,000
Convertible Preferred Stock, Shares Issued (in shares)	0	0
Convertible Preferred Stock, Shares Outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.00067	$ 0.00067
Common stock, shares authorized (in shares)	550,000,000	550,000,000
Common stock, shares issued (in shares)	288,626,570	278,462,706

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue from Contract with Customer, Including Assessed Tax	$ 2,672,000	$ 1,500,000	$ 7,860,000	$ 3,786,000
Cost of revenue
Gross profit	1,435,000	752,000	4,066,000	1,892,000
Selling, general and administrative expenses	2,278,000	1,424,000	5,794,000	4,847,000
Research and development	694,000	271,000	1,846,000	1,018,000
Operating loss	(1,537,000)	(943,000)	(3,574,000)	(3,973,000)
Other (expense) income:
Interest expense	(12,000)	(14,000)	(72,000)	(42,000)
PPP loan forgiveness	0	0	0	174,000
Tax credit (reversal)	41,000	66,000	(14,000)	66,000
Grant income	0	44,000	32,000	51,000
Total other expense:	29,000	96,000	(54,000)	249,000
Net loss	(1,508,000)	(847,000)	(3,628,000)	(3,724,000)
Net loss attributable to noncontrolling interest	(308,000)	(343,000)	(853,000)	(340,000)
Net loss attributable to common shareholders	$ (1,200,000)	$ (504,000)	$ (2,775,000)	$ (3,384,000)
Net loss per share attributable to common shareholders:
Loss per share attributable to shareholders – basic and diluted (in dollars per share)	$ (0.01)	$ 0	$ (0.01)	$ (0.01)
Weighted average number of common shares outstanding: (in shares)	287,943,346	270,665,820	284,559,487	265,812,188
Comprehensive loss:
Net loss	$ (1,508,000)	$ (847,000)	$ (3,628,000)	$ (3,724,000)
Foreign currency translation	1,000	(59,000)	(12,000)	(70,000)
Comprehensive loss	(1,507,000)	(906,000)	(3,640,000)	(3,794,000)
Comprehensive loss attributable to noncontrolling interest	(308,000)	(343,000)	(853,000)	(340,000)
Comprehensive loss attributable to common stockholders	(1,199,000)	(563,000)	(2,787,000)	(3,454,000)
Product [Member]
Revenue from Contract with Customer, Including Assessed Tax	2,529,000	1,216,000	7,392,000	2,532,000
Cost of revenue
Cost of Goods and Services Sold	(1,170,000)	(515,000)	(3,533,000)	(1,174,000)
Service [Member]
Revenue from Contract with Customer, Including Assessed Tax	143,000	284,000	468,000	1,254,000
Cost of revenue
Cost of Goods and Services Sold	$ (67,000)	$ (233,000)	$ (261,000)	$ (720,000)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Deficit) (Unaudited) - USD ($)	Clyra Medical Technologies [Member] Common Stock [Member]	Clyra Medical Technologies [Member] Additional Paid-in Capital [Member]	Clyra Medical Technologies [Member] Retained Earnings [Member]	Clyra Medical Technologies [Member] AOCI Attributable to Parent [Member]	Clyra Medical Technologies [Member] Noncontrolling Interest [Member]	Clyra Medical Technologies [Member]	BioLargo Energy Technologies, Inc (BETI) [Member] Common Stock [Member]	BioLargo Energy Technologies, Inc (BETI) [Member] Additional Paid-in Capital [Member]	BioLargo Energy Technologies, Inc (BETI) [Member] Retained Earnings [Member]	BioLargo Energy Technologies, Inc (BETI) [Member] AOCI Attributable to Parent [Member]	BioLargo Energy Technologies, Inc (BETI) [Member] Noncontrolling Interest [Member]	BioLargo Energy Technologies, Inc (BETI) [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Noncontrolling Interest [Member]	Total
Balance (in shares) at Dec. 31, 2021													255,893,726
Balance at Dec. 31, 2021													$ 171,000	$ 143,718,000	$ (139,121,000)	$ (115,000)	$ (3,720,000)	$ 933,000
Sale of stock for cash (in shares)													6,703,789
Sale of stock for cash													$ 4,000	1,198,000	0	0	0	1,202,000
Issuance of common stock for services (in shares)													86,752
Issuance of common stock for services													$ 0	17,000	0	0	0	17,000
Stock option compensation expense													0	660,000	0	0	0	660,000
Clyra Medical Technologies, Inc. (Clyra) stock options issued for services	$ 0	$ 141,000	$ 0	$ 0	$ 0	$ 141,000
Noncontrolling interest allocation													0	(528,000)	0	0	528,000	0
Net loss													0	0	(1,652,000)	0	108,000	(1,544,000)
Foreign currency translation													$ 0	0	0	(8,000)	0	(8,000)
Balance (in shares) at Dec. 31, 2021													255,893,726
Balance at Dec. 31, 2021													$ 171,000	143,718,000	(139,121,000)	(115,000)	(3,720,000)	933,000
Net loss																		(3,724,000)
Foreign currency translation																		(70,000)
Balance (in shares) at Mar. 31, 2022													262,684,267
Balance at Mar. 31, 2022													$ 175,000	145,206,000	(140,773,000)	(123,000)	(3,084,000)	1,401,000
Sale of stock for cash (in shares)													5,011,570
Sale of stock for cash													$ 4,000	944,000	0	0	0	948,000
Issuance of common stock for services (in shares)													340,891
Issuance of common stock for services													$ 0	59,000	0	0	0	59,000
Stock option compensation expense													0	234,000	0	0	0	234,000
Clyra Medical Technologies, Inc. (Clyra) stock options issued for services	0	82,000	0	0	0	82,000
Noncontrolling interest allocation													0	(103,000)	0	0	103,000	0
Net loss													0	0	(1,228,000)	0	(105,000)	(1,333,000)
Foreign currency translation													$ 0	0	0	(3,000)	0	(3,000)
Balance (in shares) at Jun. 30, 2022													268,036,728
Balance at Jun. 30, 2022													$ 179,000	146,422,000	(142,001,000)	(126,000)	(3,086,000)	1,388,000
Sale of stock for cash (in shares)													6,207,084
Sale of stock for cash													$ 4,000	1,113,000	0	0	0	1,117,000
Issuance of common stock for services (in shares)													378,828
Issuance of common stock for services													$ 1,000	95,000	0	0	0	96,000
Stock option compensation expense													0	253,000	0	0	0	253,000
Clyra Medical Technologies, Inc. (Clyra) stock options issued for services	0	85,000	0	0	0	85,000
Noncontrolling interest allocation													0	(498,000)	0	0	498,000	0
Net loss													0	0	(504,000)	0	(343,000)	(847,000)
Foreign currency translation													$ 0	0	0	(59,000)	0	(59,000)
Balance (in shares) at Dec. 31, 2022													278,462,706
Balance at Dec. 31, 2022													$ 186,000	148,435,000	(143,594,000)	(149,000)	(2,867,000)	2,011,000
Sale of stock for cash (in shares)													4,201,402
Sale of stock for cash													$ 3,000	797,000	0	0	0	800,000
Issuance of common stock for services (in shares)													930,490
Issuance of common stock for services													$ 1,000	206,000	0	0	0	207,000
Issuance of common stock in exchange for Clyra shares (in shares)													527,983
Stock option compensation expense													$ 0	195,000	0	0	0	195,000
Clyra Medical Technologies, Inc. (Clyra) stock options issued for services	0	61,000	0	0	0	61,000
Warrant issued for interest													0	30,000	0	0	0	30,000
Clyra – sales of Series A Preferred Stock	0	0	0	0	225,000	225,000	$ 0	$ 0	$ 0	$ 0	$ 550,000	$ 550,000
Clyra – Series A Preferred Stock – dividend	0	0	0	0	(27,000)	(27,000)
Noncontrolling interest allocation													0	467,000	0	0	(467,000)	0
Net loss													0	0	(247,000)	0	(247,000)	(494,000)
Foreign currency translation													$ 0	0	0	(6,000)	0	(6,000)
Balance (in shares) at Dec. 31, 2022													278,462,706
Balance at Dec. 31, 2022													$ 186,000	148,435,000	(143,594,000)	(149,000)	(2,867,000)	2,011,000
Clyra – sales of Series A Preferred Stock						1,575,000						905,000
Net loss																		(3,628,000)
Foreign currency translation																		(12,000)
Balance (in shares) at Mar. 31, 2023													284,122,581
Balance at Mar. 31, 2023													$ 190,000	150,191,000	(143,841,000)	(155,000)	(2,833,000)	3,552,000
Sale of stock for cash (in shares)													2,677,169
Sale of stock for cash													$ 2,000	492,000	0	0	0	494,000
Issuance of common stock for services (in shares)													420,911
Issuance of common stock for services													$ 0	75,000	0	0	0	75,000
Stock option compensation expense													0	222,000	0	0	0	222,000
Clyra Medical Technologies, Inc. (Clyra) stock options issued for services	0	66,000	0	0	0	66,000
Clyra – sales of Series A Preferred Stock	0	0	0	0	1,062,000	1,062,000
Clyra – Series A Preferred Stock – dividend	0	0	0	0	(45,000)	(45,000)
Noncontrolling interest allocation													0	1,461,000	0	0	(1,461,000)	0
Net loss													0	0	(1,328,000)	0	(298,000)	(1,626,000)
Foreign currency translation													$ 0	0	0	(7,000)	0	(7,000)
Biolargo Energy Technology Inc. (BETI) offering							0	0	0	0	330,000	330,000
Balance (in shares) at Jun. 30, 2023													287,220,661
Balance at Jun. 30, 2023													$ 192,000	152,507,000	(145,169,000)	(162,000)	(3,245,000)	4,123,000
Sale of stock for cash (in shares)													1,190,223
Sale of stock for cash													$ 1,000	202,000	0	0	0	203,000
Issuance of common stock for services (in shares)													215,686
Issuance of common stock for services													$ 0	37,000	0	0	0	37,000
Stock option compensation expense													0	680,000	0	0	0	680,000
Clyra Medical Technologies, Inc. (Clyra) stock options issued for services	0	45,000	0	0	0	45,000
Clyra – sales of Series A Preferred Stock	0	0	0	0	288,000	288,000
Clyra – Series A Preferred Stock – dividend	0	0	0	0	(80,000)	(80,000)
Noncontrolling interest allocation													0	(68,000)	0	0	68,000	0
Net loss													0	0	(1,200,000)	0	(308,000)	(1,508,000)
Foreign currency translation													$ 0	$ 0	$ 0	$ 1,000	$ 0	$ 1,000
Biolargo Energy Technology Inc. (BETI) offering							$ 0	$ 0	$ 0	$ 0	$ 25,000	$ 25,000
Clyra Medical Technologies, Inc. (Clyra) stock option exercise	$ 0	$ 3,000	$ 0	$ 0	$ 0	$ 3,000

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity (Deficit) (Unaudited) 2 - USD ($)	Clyra Medical Technologies [Member] Common Stock [Member]	Clyra Medical Technologies [Member] Additional Paid-in Capital [Member]	Clyra Medical Technologies [Member] Retained Earnings [Member]	Clyra Medical Technologies [Member] AOCI Attributable to Parent [Member]	Clyra Medical Technologies [Member] Noncontrolling Interest [Member]	Clyra Medical Technologies [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Noncontrolling Interest [Member]	Total
Balance (in shares) at Dec. 31, 2021							255,893,726
Balance at Dec. 31, 2021							$ 171,000	$ 143,718,000	$ (139,121,000)	$ (115,000)	$ (3,720,000)	$ 933,000
Sale of stock for cash (in shares)							6,703,789
Sale of stock for cash							$ 4,000	1,198,000	0	0	0	1,202,000
Issuance of common stock for services (in shares)							86,752
Issuance of common stock for services							$ 0	17,000	0	0	0	17,000
Stock option compensation expense							0	660,000	0	0	0	660,000
Clyra Medical Technologies, Inc. (Clyra) stock options issued for services	$ 0	$ 141,000	$ 0	$ 0	$ 0	$ 141,000
Noncontrolling interest allocation							0	(528,000)	0	0	528,000	0
Net loss							0	0	(1,652,000)	0	108,000	(1,544,000)
Foreign currency translation							$ 0	0	0	(8,000)	0	(8,000)
Balance (in shares) at Mar. 31, 2022							262,684,267
Balance at Mar. 31, 2022							$ 175,000	145,206,000	(140,773,000)	(123,000)	(3,084,000)	1,401,000
Balance (in shares) at Dec. 31, 2021							255,893,726
Balance at Dec. 31, 2021							$ 171,000	143,718,000	(139,121,000)	(115,000)	(3,720,000)	933,000
Net loss												(3,724,000)
Foreign currency translation												(70,000)
Balance (in shares) at Sep. 30, 2022							274,622,640
Balance at Sep. 30, 2022							$ 184,000	147,470,000	(142,505,000)	(185,000)	(2,931,000)	2,033,000
Balance (in shares) at Mar. 31, 2022							262,684,267
Balance at Mar. 31, 2022							$ 175,000	145,206,000	(140,773,000)	(123,000)	(3,084,000)	1,401,000
Sale of stock for cash (in shares)							5,011,570
Sale of stock for cash							$ 4,000	944,000	0	0	0	948,000
Issuance of common stock for services (in shares)							340,891
Issuance of common stock for services							$ 0	59,000	0	0	0	59,000
Stock option compensation expense							0	234,000	0	0	0	234,000
Clyra Medical Technologies, Inc. (Clyra) stock options issued for services	0	82,000	0	0	0	82,000
Noncontrolling interest allocation							0	(103,000)	0	0	103,000	0
Net loss							0	0	(1,228,000)	0	(105,000)	(1,333,000)
Foreign currency translation							$ 0	0	0	(3,000)	0	(3,000)
Balance (in shares) at Jun. 30, 2022							268,036,728
Balance at Jun. 30, 2022							$ 179,000	146,422,000	(142,001,000)	(126,000)	(3,086,000)	1,388,000
Sale of stock for cash (in shares)							6,207,084
Sale of stock for cash							$ 4,000	1,113,000	0	0	0	1,117,000
Issuance of common stock for services (in shares)							378,828
Issuance of common stock for services							$ 1,000	95,000	0	0	0	96,000
Stock option compensation expense							0	253,000	0	0	0	253,000
Clyra Medical Technologies, Inc. (Clyra) stock options issued for services	0	85,000	0	0	0	85,000
Noncontrolling interest allocation							0	(498,000)	0	0	498,000	0
Net loss							0	0	(504,000)	0	(343,000)	(847,000)
Foreign currency translation							$ 0	0	0	(59,000)	0	(59,000)
Balance (in shares) at Sep. 30, 2022							274,622,640
Balance at Sep. 30, 2022							$ 184,000	147,470,000	(142,505,000)	(185,000)	(2,931,000)	2,033,000
Balance (in shares) at Dec. 31, 2022							278,462,706
Balance at Dec. 31, 2022							$ 186,000	148,435,000	(143,594,000)	(149,000)	(2,867,000)	2,011,000
Sale of stock for cash (in shares)							4,201,402
Sale of stock for cash							$ 3,000	797,000	0	0	0	800,000
Issuance of common stock for services (in shares)							930,490
Issuance of common stock for services							$ 1,000	206,000	0	0	0	207,000
Stock option compensation expense							0	195,000	0	0	0	195,000
Clyra Medical Technologies, Inc. (Clyra) stock options issued for services	0	61,000	0	0	0	61,000
Noncontrolling interest allocation							0	467,000	0	0	(467,000)	0
Net loss							0	0	(247,000)	0	(247,000)	(494,000)
Foreign currency translation							$ 0	0	0	(6,000)	0	(6,000)
Balance (in shares) at Mar. 31, 2023							284,122,581
Balance at Mar. 31, 2023							$ 190,000	150,191,000	(143,841,000)	(155,000)	(2,833,000)	3,552,000
Balance (in shares) at Dec. 31, 2022							278,462,706
Balance at Dec. 31, 2022							$ 186,000	148,435,000	(143,594,000)	(149,000)	(2,867,000)	2,011,000
Net loss												(3,628,000)
Foreign currency translation												(12,000)
Balance (in shares) at Sep. 30, 2023							288,626,570
Balance at Sep. 30, 2023							$ 193,000	153,406,000	(146,369,000)	(161,000)	(3,252,000)	3,817,000
Balance (in shares) at Mar. 31, 2023							284,122,581
Balance at Mar. 31, 2023							$ 190,000	150,191,000	(143,841,000)	(155,000)	(2,833,000)	3,552,000
Sale of stock for cash (in shares)							2,677,169
Sale of stock for cash							$ 2,000	492,000	0	0	0	494,000
Issuance of common stock for services (in shares)							420,911
Issuance of common stock for services							$ 0	75,000	0	0	0	75,000
Stock option compensation expense							0	222,000	0	0	0	222,000
Clyra Medical Technologies, Inc. (Clyra) stock options issued for services	0	66,000	0	0	0	66,000
Noncontrolling interest allocation							0	1,461,000	0	0	(1,461,000)	0
Net loss							0	0	(1,328,000)	0	(298,000)	(1,626,000)
Foreign currency translation							$ 0	0	0	(7,000)	0	(7,000)
Balance (in shares) at Jun. 30, 2023							287,220,661
Balance at Jun. 30, 2023							$ 192,000	152,507,000	(145,169,000)	(162,000)	(3,245,000)	4,123,000
Sale of stock for cash (in shares)							1,190,223
Sale of stock for cash							$ 1,000	202,000	0	0	0	203,000
Issuance of common stock for services (in shares)							215,686
Issuance of common stock for services							$ 0	37,000	0	0	0	37,000
Stock option compensation expense							0	680,000	0	0	0	680,000
Clyra Medical Technologies, Inc. (Clyra) stock options issued for services	$ 0	$ 45,000	$ 0	$ 0	$ 0	$ 45,000
Noncontrolling interest allocation							0	(68,000)	0	0	68,000	0
Net loss							0	0	(1,200,000)	0	(308,000)	(1,508,000)
Foreign currency translation							$ 0	0	0	1,000	0	1,000
Balance (in shares) at Sep. 30, 2023							288,626,570
Balance at Sep. 30, 2023							$ 193,000	$ 153,406,000	$ (146,369,000)	$ (161,000)	$ (3,252,000)	$ 3,817,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
Consolidated Statements of Cash Flows (Unaudited) - USD ($)	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities
Net loss	$ (3,628,000)	$ (3,724,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock option compensation expense	1,269,000	1,455,000
Common stock issued for services	319,000	172,000
Bad debt expense	101,000	0
Excess and obsolete inventory	54,000	0
Amortization of right-of-use operating lease assets	90,000	0
Interest expense related to amortization of the discount on note payable	3,000	13,000
Fair value of warrant issued for interest	30,000	0
PPP loan forgiveness	0	(174,000)
Loss on investment in South Korean joint venture	18,000	15,000
Depreciation expense	94,000	28,000
Changes in assets and liabilities:
Accounts receivable	(490,000)	(371,000)
Inventories	(58,000)	(19,000)
Prepaid expenses and other assets	101,000	(85,000)
Deferred revenue	(15,000)	(83,000)
Lease liability, net	(78,000)	0
Customer deposits	(62,000)	30,000
Net cash used in operating activities	(2,363,000)	(2,803,000)
Cash flows from investing activities
Equipment purchases	(332,000)	(164,000)
Net cash used in investing activities	(332,000)	(164,000)
Cash flows from financing activities
Proceeds from sale of common stock	1,497,000	3,267,000
Repayment of note payable and vehicle loan	(55,000)	0
Repayment by Clyra on inventory line of credit	(27,000)	(24,000)
Proceeds from sale of Clyra Medical preferred stock	1,575,000	100,000
Proceeds from Clyra Medical stock option exercise	3,000	0
Net cash provided by financing activities	3,898,000	3,343,000
Net effect of foreign currency translation	(12,000)	(70,000)
Net change in cash	1,191,000	306,000
Cash at beginning of year	1,851,000	962,000
Cash at end of period	3,042,000	1,268,000
Supplemental disclosures of cash flow information
Interest	39,000	11,000
Income taxes	0	0
Short-term lease payments not included in lease liability	43,000	90,000
Non-cash investing and financing activities
Equipment added using capital lease	80,000	0
Right of use	0	433,000
Series A Preferred Stock [Member]
Non-cash investing and financing activities
Preferred Series A dividend	152,000	0
Conversion of Intercompany Receivable into Clyra Shares [Member]
Non-cash investing and financing activities
Allocation of noncontrolling interest	1,860,000	1,129,000
BETI Common Stock [Member]
Cash flows from financing activities
Proceeds from sale of common stock	905,000	0
Entities, Excluding Partially Owned Subsidiary [Member]
Changes in assets and liabilities:
Accounts payable and accrued expenses	(52,000)	(40,000)
Partially Owned Subsidiary [Member]
Changes in assets and liabilities:
Accounts payable and accrued expenses	$ (59,000)	$ (20,000)

Note 1 - Business and Organizat

Note 1 - Business and Organization	9 Months Ended
Note 1 - Business and Organization	Sep. 30, 2023
Notes to Financial Statements
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Note 1. Description of Business BioLargo, Inc. (“BioLargo”, or the “Company”) invents, develops, and commercializes innovative platform technologies to solve challenging environmental problems like PFAS contamination (per- and polyfluoroalkyl substances), advanced water and wastewater treatment, industrial odor control, air quality control, infection control, and myriad environmental remediation challenges. Our business strategy is straightforward: we invent or acquire technologies that we believe have the potential to be disruptive in large commercial markets; we develop and validate these technologies to advance and promote their commercial success as we leverage our considerable scientific, engineering, and entrepreneurial talent; we then monetize these technical assets through a variety of business structures that may Organization We are a Delaware corporation formed in 1991. 2006; 2009; 2022; 2014; 2022; 2016. 2012 8 2017 9 2022 10 2, Liquidity / Going Concern The accompanying consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of our business. For the nine September 30, 2023 11 September 30, 2023 During the nine September 30, 2023 3 3 6 8 10 September 30, 2023 13 September 30, 2023 4 4 2024 8 If we are unable to rely on our current arrangement with Lincoln Park to fund our working capital requirements, we will have to rely on other forms of financing, and there is no The foregoing factors raise substantial doubt about our ability to continue as a going concern, unless we are able to continue to raise funds through stock sales to Lincoln Park or other private financings, or attain a reasonable threshold of operating efficiencies and achieve profitable operations. The consolidated financial statements do not

Note 2 - Summary of Significant

Note 2 - Summary of Significant Accounting Policies	9 Months Ended
Note 2 - Summary of Significant Accounting Policies	Sep. 30, 2023
Notes to Financial Statements
Significant Accounting Policies [Text Block]	Note 2. Principles of Consolidation The consolidated financial statements include the accounts of the Company, its wholly owned subsidiaries, and partially owned subsidiaries BETI, BLEST and Clyra Medical. All intercompany accounts and transactions have been eliminated. Foreign Currency The Company has designated the functional currency of BioLargo Water, Inc., our Canadian subsidiary, to be the Canadian dollar. Therefore, translation gains and losses resulting from differences in exchange rates are recorded in accumulated other comprehensive income. Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three one $250,000 not As of September 30, 2023 December 31, 2022 September 30, 2023 December 31, 2022 BioLargo, Inc. and subsidiaries $ 2,280 $ 1,681 Clyra Medical Technologies, Inc. 762 170 Total $ 3,042 $ 1,851 Accounts Receivable In June 2016, 2016 13, January 1, 2023 Accounts receivable are customer obligations that are unconditional. Accounts receivable are presented net of an allowance for doubtful accounts for expected credit losses, which represents an estimate of amounts that may not no not September 30, 2023 December 31, 2022 Credit Concentration We have a limited number of customers that account for significant portions of our revenue. During the three nine September 30, 2023 2022 10% Three Months Nine Months September 30, 2023 September 30, 2022 September 30, 2023 September 30, 2022 Customer A 74% 4% 76% 44% Customer B <10% <10% <10% 14% Customer C <10% <10% <10% <10% At September 30, 2023 December 31, 2022 September 30, 2023 December 31, 2022 Customer A 67 % 11 % Customer B <10% 31 % Customer D <10% 15 % Inventory Inventories are stated at the lower of cost or net realizable value using the average cost method. The allowance for obsolete inventory as of September 30, 2023 December 31, 2022 September 30, 2023 December 31, 2022 Raw material $ 78 $ 46 Finished goods 44 74 Total $ 122 $ 120 Other Non-Current Assets Other non-current assets consisted of (i) security deposits related to our business offices, (ii) three October 22, 2021, September 30, 2023 December 31, 2022 Patents $ 34 $ 34 Security deposits 35 35 Tax credit receivable — 55 Total $ 69 $ 124 Equity Method of Accounting On March 20, 2020, We account for our investment in the joint venture under the equity method of accounting. We have determined that while we have significant influence over the joint venture through our technology license and our position on the Board of Directors, we do not three nine September 30, 2023 2022, Impairment Long-lived and definite lived intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not three nine September 30, 2023 2022 Earnings (Loss) Per Share We report basic and diluted earnings (loss) per share (“EPS”) for common and common share equivalents. Basic EPS is computed by dividing reported earnings by the weighted average shares outstanding. Diluted EPS is computed by adding to the weighted average shares the dilutive effect if convertible notes payable, stock options and warrants were exercised into common stock. For the three nine September 30, 2023 2022 Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and revenues and expenses during the period reported. Actual results could differ from those estimates. Estimates are used when accounting for stock-based transactions, debt transactions, derivative liabilities, allowance for bad debt, asset depreciation and amortization, impairment expense, among others. The methods, estimates and judgments we use in applying these most critical accounting policies have a significant impact on the results of our financial statements. Share-Based Compensation Expense We recognize compensation expense for stock option awards on a straight-line basis over the applicable service period of the award, which is the vesting period. Fair value is determined on the grant date. Share-based compensation expense is based on the grant date fair value estimated using the Black-Scholes Option Pricing Model. For stock and stock options issued to consultants and other non-employees for services, the Company measures and records an expense as of the earlier of the date at which either: a commitment for performance by the non-employee has been reached or the non-employee’s performance is complete. The equity instruments are measured at the current fair value, and for stock options, the instruments are measured at fair value using the Black Scholes option model. The following methodology and assumptions were used to calculate share-based compensation for the nine September 30, 2023 2022 2023 2022 Non Plan 2018 Plan Non Plan 2018 Plan Risk free interest rate 4.15 % 3.48 - 4.15 % 2.32 - 3.83 % 2.32 - 3.83 % Expected volatility 112 % 112 - 114 % 115 - 117 % 115 - 117 % Expected dividend yield — — — — Forfeiture rate — — — — Life in years 10 10 10 10 Expected price volatility is the measure by which our stock price is expected to fluctuate during the expected term of an option. The expected volatility is derived from the historical daily change in the market price of our common stock, as we believe that historical volatility is the best indicator of future volatility. The risk-free interest rate used in the Black-Scholes calculation is based on the prevailing U.S. Treasury yield as determined by the U.S. Federal Reserve. We have never paid any cash dividends on our common stock and do not Warrants Warrants issued with our convertible and non-convertible debt instruments are accounted for under the fair value and relative fair value method. The warrant is first not. not not Non-Cash Transactions We determine the value assigned to each intangible we acquire, and/or services or products received for non-cash consideration of our common stock based on the market price of our common stock issued as consideration, at the date of the agreement of each transaction or when the service is rendered or product is received. Revenue Recognition We account for revenue in accordance with ASC 606, Step 1: Step 2: Step 3: Step 4: Step 5: The Company’s products are sold through a contract with the customer and a written purchase order, in which the details of the contract are defined including the transaction price and method of shipment. The only performance obligation is to create and ship the product, and each product has separate pricing. Revenue is recognized at a point in time when the goods are shipped if the agreement is FOB manufacturer, and when goods are delivered if FOB destination. Revenue is recognized with a reduction for sales discounts, as appropriate and negotiated in the customer’s purchase order. Service contracts are performed through a written contract, which specifies the performance obligations and the rate at which the services will be billed, typically by time and materials. Each service is separately negotiated and priced. Revenue is recognized as services are performed and completed, or, for services related to product installations, at the completion of the installation. A few contracts have called for milestone or fixed cost payments, where we invoice an agreed-to amount per month for the life of the contract. In these instances, completed work, billed hourly, is recognized as revenue. If the billing amount is greater or lesser than the completed work, a receivable or payable is created. These accounts are adjusted upon additional billings as the work is completed. To date, there have been no The Company has outstanding contract liability obligations of $2,000 as of September 30, 2023 nine September 30, 2023 September 30, 2023 As we generate revenues from royalties or license fees from our intellectual property, a licensee will pay a license fee in one third Government Grants We have been awarded multiple research grants from the private and public Canadian research programs. The income we receive directly from grants is recorded as other income. We have been awarded over 80 first 2015. third third six eighteen not The grants typically provide for (i) recurring monthly amounts, (ii) reimbursement of costs for research talent for which we invoice to request payment, and (iii) ancillary cost reimbursement for research talent travel related costs. All awarded grants have specific requirements on how the money is spent, typically to employ researchers. None may Not no Income Taxes The asset and liability approach is used to recognize deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the carrying amounts and the tax bases of asset and liabilities. Deferred tax assets and liabilities are determined based on the differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The effect on deferred tax asset and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. We account for uncertainties in income tax law under a comprehensive model for the financial statement recognition, measurement, presentation, and disclosure of uncertain tax positions taken or expected to be taken in income tax returns as prescribed by generally accepted accounting principles (“GAAP”). Under GAAP, the tax effects of a position are recognized only if it is “more-likely-than- not” not not” no September 30, 2023 December 31, 2022 The Company assessed its earnings history, trends and estimates of future earnings and determined that the deferred tax asset could not September 30, 2023 December 31, 2022 100% The Company recognizes interest and penalties on income taxes as a component of income tax expense, should such an expense be realized. Fair Value of Financial Instruments Management believes the carrying amounts of the Company’s financial instruments as of September 30, 2023 December 31, 2022 Tax Credits Our research and development activities in Canada may not During the three September 30, 2023, Leases At inception of a lease contract, we assess whether the contract is, or contains, a lease. Our assessment is based on: ( 1 2 3 not no September 30, 2023 nine not not 12 not As of September 30, 2023 Property and Equipment Property and equipment includes machinery and leasehold improvements and is stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which range from 3 - 5 years or the remaining lease term. Newly built leaseholds, additions, renewals, and betterments that significantly extend the life of the asset are capitalized. The Company is currently constructing a facility and purchasing equipment for producing sodium sulfur batteries. Expenditures for repairs and maintenance are charged to expense as incurred. For assets sold or otherwise disposed of, the cost and related accumulated depreciation and amortization are removed from the accounts, and any related gain or loss is reflected in income for the period. Recent Accounting Pronouncements Currently there are no

Note 3 - Sale of Stock for Cash

Note 3 - Sale of Stock for Cash	9 Months Ended
Note 3 - Sale of Stock for Cash	Sep. 30, 2023
Notes to Financial Statements
Stock Purchase Agreement [Text Block]	Note 3. Lincoln Park Financing On December 13, 2022, “2022 three may three 12 no first 2022 1 December 23, 2022. January 19, 2023. During the three nine September 30, 2023 During the three nine September 30, 2022 Unit Offerings We did not three September 30, 2023. nine September 30, 2023, six five 6, During the three nine September 30, 2022, thirty six five 6,

Note 4 - Debt Obligations

Note 4 - Debt Obligations	9 Months Ended
Note 4 - Debt Obligations	Sep. 30, 2023
Notes to Financial Statements
Debt Disclosure [Text Block]	Note 4. The following table summarizes our debt obligations outstanding as of September 30, 2023 December 31, 2022 not 8, September 30, 2023 December 31, 2022 Current portion of debt: SBA Paycheck Protection Program loan $ 43 $ 43 Vehicle loan, current portion 13 — Convertible note payable, matures March 1, 2023 — 50 SBA EIDL Loan, matures July 2050, current portion 10 10 Debt discount, net of amortization — (3 ) Total current portion of debt $ 66 $ 100 Long-term debt: SBA Paycheck Protection Program loans, matures May 2025 $ 97 $ 97 Vehicle loan, matures March 2029 58 — SBA EIDL Loan, matures July 2050 138 140 Total long-term debt, net of current $ 293 $ 237 Total $ 359 $ 337 For the three nine September 30, 2023 For the three nine September 30, 2022 Vehicle loan On February 7, 2023, March 7, 2029. Convertible note payable, matures March 1, 2023 On March 6, 2023, 10 five 6 SBA Program Loans On February 7, 2022, September 30, 2023 On May 12, 2022, May 2025. In July 2020, July 2050.

Note 5 - Share-based Compensati

Note 5 - Share-based Compensation	9 Months Ended
Note 5 - Share-based Compensation	Sep. 30, 2023
Notes to Financial Statements
Compensation and Employee Benefit Plans [Text Block]	Note 5. Issuance of Common Stock in exchange for Services Payment of Officer Salaries On September 30, 2023 two June 30, 2023, March 31, 2023, On September 30, 2022, Shares issued to Officers are unvested at the date of grant and subject to a lock-up agreement restricting vesting and sale until the earlier of (i) the consummation of a sale (in a single transaction or in a series of related transactions) of BioLargo by means of a sale of (a) a majority of the then outstanding common stock of BioLargo (whether by merger, consolidation, sale or transfer of common stock, reorganization, recapitalization or otherwise) or (b) all or substantially all of the assets of BioLargo; and (ii) the successful commercialization of BioLargo’s products or technologies as demonstrated by its receipt of at least $3,000,000 in cash, or the recognition of $3,000,000 in revenue, over a 12 Payment of Consultant and Vendor Fees On September 30, 2023 June 30, 2023, March 31, 2023, On September 30, 2022, June 30, 2022, March 31, 2022, All of these offerings and sales were made in reliance on the exemption from registration contained in Section 4 2 not Stock Option Expense During the three nine September 30, 2023 three nine September 30, 2022 2018 three nine September 30, 2023 three nine September 30, 2022 8. 2018 On June 22, 2018, 2018 “2018 may June 22, 2028. 2018 2018 January 1 st September 30, 2023 Activity for our stock options under the 2018 nine September 30, 2023 2022 Options Outstanding Exercise Price per share Weighted Average Price per share Aggregate intrinsic Value(1) Balance, December 31, 2022 28,484,549 $ 0.12 – 0.43 $ 0.19 Granted 8,219,920 0.17 – 0.20 $ 0.18 Balance, September 30, 2023 36,704,469 0.12 – 0.43 $ 0.19 Unvested (4,648,922 ) 0.12 – 0.27 $ 0.15 Vested, September 30, 2023 32,055,547 0.12 – 0.43 $ 0.19 $ 278,000 Balance, December 31, 2021 23,186,142 0.16 – 0.43 $ 0.19 Granted 4,748,212 0.18 – 0.27 $ 0.22 Balance, September 30, 2022 27,934,354 0.12 – 0.43 $ 0.19 ( 1 September 30, 2023 The options granted to purchase 8,219,920 shares during the nine September 30, 2023 March 31, 2023 ( June 30, 2023 ( September 30, 2023 ( four The options granted to purchase 4,748,212 shares during the nine September 30, 2022 $246,000; four Chief Financial Officer Contract Extension On March 21, 2023, February 1, 2008 ( March 21, 2023 ( one January 31, 2024 ( As the sole compensation for the Extended Term, Mr. Dargan was issued an option (“Option”) to purchase 25,000 shares of the Company’s common stock for each month during the Extended Term (thus, an option to purchase 300,000 shares reflecting an extended term of 12 March 21, 2023, March 31, 2023, March 21, 2023, ten 2018 The Option is Mr. Dargan’s sole compensation for the Extended Term. As was the case in all prior terms of his engagement, there is no no not 2007 On September 7, 2007, April 29, 2011, 2007 “2007 may September 7, 2017. September 2017, Activity for our stock options under the 2007 nine September 30, 2023 2022 Options Outstanding Exercise price per share Weighted Average Price per share Aggregate intrinsic Value(1) Balance, December 31, 2022 1,904,085 $ 0.28 – 0.69 $ 0.56 Expired (340,000 ) 0.28 0.30 0.30 Balance, September 30, 2023 1,564,085 0.28 – 0.69 $ 0.61 $ — Balance, December 31, 2021 2,879,246 0.23 – 0.94 $ 0.49 Expired (975,161 ) 0.28 0.36 Balance, September 30, 2022 1,904,085 $ 0.24 – 0.94 $ 0.56 ( 1 September 30, 2023 Non-Plan Options Activity of our non-plan stock options issued for the nine September 30, 2023 2022 Non-plan Options outstanding Exercise price per share Weighted averageprice per share Aggregate intrinsic Value(1) Balance, December 31, 2022 19,023,829 $ 0.12 – 0.83 $ 0.39 Granted 60,040 0.18 – 0.20 0.20 Expired (1,205,550 ) 0.30 0.30 Balance, September 30, 2023 17,878,319 $ 0.12 – 0.83 $ 0.39 Unvested (507,500 ) 0.45 0.45 Vested, September 30, 2023 17,370,819 $ 0.12 – 0.83 $ 0.39 $ 28,000 Balance, December 31, 2021 20,119,207 $ 0.17 – 1.00 $ 0.41 Granted 105,797 0.23 - 0.27 0.26 Balance, September 30, 2022 20,225,004 $ 0.17 – 1.00 $ 0.39 ( 1 September 30, 2023 During the nine September 30, 2023 During the nine September 30, 2022,

Note 6 - Warrants

Note 6 - Warrants	9 Months Ended
Note 6 - Warrants	Sep. 30, 2023
Notes to Financial Statements
Warrants [Text Block]	Note 6. We have certain warrants outstanding to purchase our common stock, at various prices, as described in the following table: Warrants outstanding Exercise price per share Weighted average price per share Aggregate intrinsic value(1) Balance, December 31, 2022 49,023,398 $ 0.13 – 1.00 $ 0.26 Granted 10,669,896 0.21 – 0.29 0.26 Expired (11,313,584 ) 0.10 - 0.48 0.23 Balance, September 30, 2023 48,379,710 $ 0.13 – 1.00 $ 0.27 $ 18,000 Balance, December 31, 2021 36,765,502 $ 0.16 – 1.00 $ 0.27 Granted 27,137,048 0.20 – 0.29 0.23 Expired (10,273,722 ) 0.19 – 0.48 0.25 Balance, September 30, 2022 53,628,828 $ 0.14 – 1.00 $ 0.26 ( 1 September 30, 2023 Warrants issued in Unit Offerings During the nine September 30, 2023 3 six five During the nine September 30, 2022, 3 nine five Warrant issued in conjunction with amendment to note payable On March 6, 2023, 4, March 1, 2023”) five Fair Value – Interest Expense To determine interest expense related to our outstanding warrants issued in conjunction with debt offerings, the fair value of each award grant is estimated on the date of grant using the Black-Scholes option pricing model and the relative fair values are amortized over the life of the warrant. For the determination of expense of warrants issued for services, extinguishment of debt and settlement management also uses the option-pricing model. The principal assumptions we used in applying this model were as follows: 2023 2022 Risk free interest rate 3.88 – 4.27 % 3.69 – 3.88 % Expected volatility 40 – 95 % 40 % Expected dividend yield — — Forfeiture rate — — Expected life in years .5 – 5 3 The risk-free interest rate is based on U.S. Treasury yields in effect at the time of grant. Expected volatilities are based on historical volatility of our common stock. The expected life in years is based on the contract term of the warrant.

Note 7 - Accounts Payable and A

Note 7 - Accounts Payable and Accrued Expenses	9 Months Ended
Note 7 - Accounts Payable and Accrued Expenses	Sep. 30, 2023
Notes to Financial Statements
Accounts Payable and Accrued Liabilities Disclosure [Text Block]	Note 7. As of September 30, 2023 Category BioLargo ONM BLEST Water BETI Intercompany amounts Totals Accounts payable $ 208 $ 417 $ 5 $ 91 $ 31 $ (82 ) $ 670 Accrued payroll 40 85 69 — — — 194 Accrued interest 25 — — — — — 25 Total $ 889 As of December 31, 2022 Category BioLargo ONM BLEST Water Intercompany amounts Totals Accounts payable $ 187 $ 486 $ 7 $ 119 $ (82 ) $ 717 Accrued payroll 20 58 120 — — 198 Accrued interest 25 — — — — 25 Total $ 940 See Note 8,

Note 8 - Noncontrolling Interes

Note 8 - Noncontrolling Interest - Clyra Medical	9 Months Ended
Note 8 - Noncontrolling Interest - Clyra Medical	Sep. 30, 2023
Notes to Financial Statements
Noncontrolling Interest Disclosure [Text Block]	Note 8. Clyra Medical As discussed in Note 2 Debt Obligations of Clyra Medical Promissory Note On April 8, 2022, April 8, 2024, may Line of Credit On June 30, 2020, may On December 13, 2022, September 30, 2024, January 9, 2023, As of September 30, 2023 December 31, 2022 $161,000. Equity Transactions As of September 30, 2023 December 31, 2022 September 30, 2023 December 31, 2022, BioLargo Conversion of Intercompany Balances In July 2023, March 2, 2022, Sales of Series A Preferred Stock During the three September 30, 2023 seven nine September 30, 2023 35 no one may Each investor also entered into an agreement with BioLargo whereby the investor may 20% 30 may January 1, 2025, June 30, 2026. Clyra Stock Options Clyra Options Outstanding Exercise price per share Weighted average price per share Balance, December 31, 2022 15,833 $ 1.00 – 310 $ 5.53 Exercised (2,964 ) $ 1.00 $ 1.00 Granted 1,215 1.00 – 271 171.99 Balance, September 30, 2023 14,084 $ 1.00 – 310 $ 20.85 Balance, December 31, 2021 14,004 $ 1.00 $ 1.00 Granted 1,403 1.00 1.00 Balance, September 30, 2022 15,407 $ 1.00 $ 1.00 Clyra issues options to its employees and consultants in lieu of compensation owed on a regular basis. The fair value of the options issued totaled $45,000 and $172,000 in the three nine September 30, 2023 three nine September 30, 2022 no During the three September 30, 2023, two September 30, 2023 December 31, 2022 Risk free interest rate 3.48 – 4.15 % 2 % Expected volatility 40 – 49 % 40 % Expected dividend yield — — Forfeiture rate — — Expected life in years 10 10 Accounts Payable and Accrued Expenses At September 30, 2023 December 31, 2022 Category 2023 2022 Accounts payable $ 158 $ 186 Accrued payroll 12 45 Accrued interest 8 7 Accrued dividend 152 — Total $ 330 $ 238

Note 9 - BioLargo Engineering,

Note 9 - BioLargo Engineering, Science and Technologies, LLC	9 Months Ended
	Sep. 30, 2023
Notes to Financial Statements
Wholly-Owned Subsidiary [Text Block]	Note 9. In September 2017, six 11 two no five five March 31, 2018 ( not first not September 2018. The BLEST Compensation Committee has met regularly since the subsidiary commenced operations. In 2018, not not December 31, 2021, January 2022, one one December 31, 2021. December 2022, one one $135,000 December 31, 2022.

Note 10 - BioLargo Energy Techn

Note 10 - BioLargo Energy Technologies, Inc.	9 Months Ended
Note 10 - BioLargo Energy Technologies, Inc.	Sep. 30, 2023
Notes to Financial Statements
Noncontrolling Interest Disclosure [Text Block]	Note 8. Clyra Medical As discussed in Note 2 Debt Obligations of Clyra Medical Promissory Note On April 8, 2022, April 8, 2024, may Line of Credit On June 30, 2020, may On December 13, 2022, September 30, 2024, January 9, 2023, As of September 30, 2023 December 31, 2022 $161,000. Equity Transactions As of September 30, 2023 December 31, 2022 September 30, 2023 December 31, 2022, BioLargo Conversion of Intercompany Balances In July 2023, March 2, 2022, Sales of Series A Preferred Stock During the three September 30, 2023 seven nine September 30, 2023 35 no one may Each investor also entered into an agreement with BioLargo whereby the investor may 20% 30 may January 1, 2025, June 30, 2026. Clyra Stock Options Clyra Options Outstanding Exercise price per share Weighted average price per share Balance, December 31, 2022 15,833 $ 1.00 – 310 $ 5.53 Exercised (2,964 ) $ 1.00 $ 1.00 Granted 1,215 1.00 – 271 171.99 Balance, September 30, 2023 14,084 $ 1.00 – 310 $ 20.85 Balance, December 31, 2021 14,004 $ 1.00 $ 1.00 Granted 1,403 1.00 1.00 Balance, September 30, 2022 15,407 $ 1.00 $ 1.00 Clyra issues options to its employees and consultants in lieu of compensation owed on a regular basis. The fair value of the options issued totaled $45,000 and $172,000 in the three nine September 30, 2023 three nine September 30, 2022 no During the three September 30, 2023, two September 30, 2023 December 31, 2022 Risk free interest rate 3.48 – 4.15 % 2 % Expected volatility 40 – 49 % 40 % Expected dividend yield — — Forfeiture rate — — Expected life in years 10 10 Accounts Payable and Accrued Expenses At September 30, 2023 December 31, 2022 Category 2023 2022 Accounts payable $ 158 $ 186 Accrued payroll 12 45 Accrued interest 8 7 Accrued dividend 152 — Total $ 330 $ 238
BioLargo Energy Technologies, Inc (BETI) [Member]
Notes to Financial Statements
Noncontrolling Interest Disclosure [Text Block]	Note 10. BioLargo Energy Technologies, Inc. (“BETI”) was formed for the purpose of commercializing a sodium-sulfur battery technology. BioLargo purchased 9,000,000 shares of its common stock upon its formation, and was its sole stockholder. During the three September 30, 2023 one nine September 30, 2023 16 may 20 2024. As of September 30, 2023

Note 11 - Business Segment Info

Note 11 - Business Segment Information	9 Months Ended
Note 11 - Business Segment Information	Sep. 30, 2023
Notes to Financial Statements
Segment Reporting Disclosure [Text Block]	Note 11. BioLargo has five 1. ONM Environmental -- which sells odor and volatile organic control products and services (located in Westminster, California); 2. Clyra Medical Technologies (“Clyra Medical”) -- which develops and sells medical products based on our technologies; 3. BLEST -- which provides professional engineering services on a time and materials basis for outside clients and supports our internal operations as needed (located in Oak Ridge, Tennessee); 4. BioLargo Water (“Water”) – our research, development and innovation group operating out of the University of Alberta, Edmonton, Canada; and 5. BioLargo Energy Technologies, Inc. (“BETI”) – formed to commercialize our sodium-sulfur battery technology. Other than ONM Environmental, during the last three none third The segment information for the three nine September 30, 2023 2022 Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Revenue BioLargo corporate $ — $ 2 $ — $ 4 ONM Environmental 2,513 1,199 7,374 2,499 BLEST 843 401 1,742 1,613 BETI — — — — Water 22 1 31 1 Clyra Medical 14 17 20 34 Intersegment revenue (720 ) (120 ) (1,307 ) (365 ) Total $ 2,672 $ 1,500 $ 7,860 $ 3,786 Research and development expense BioLargo corporate $ (234 ) $ (140 ) $ (665 ) $ (570 ) ONM Environmental (14 ) — (14 ) — BLEST (433 ) (100 ) (971 ) (288 ) BETI (537 ) — (840 ) — Water (128 ) (119 ) (401 ) (446 ) Clyra Medical (68 ) (31 ) (262 ) (73 ) Intersegment R&D 720 119 1,307 359 Total $ (694 ) $ (271 ) $ (1,846 ) $ (1,018 ) Operating income (loss) BioLargo corporate $ (797 ) $ (783 ) $ (2,230 ) $ (2,925 ) ONM Environmental 969 400 2,786 418 BLEST (568 ) (179 ) (1,388 ) (158 ) BETI (559 ) — (943 ) — Water (155 ) (141 ) (549 ) (572 ) Clyra Medical (427 ) (240 ) (1,250 ) (736 ) Total $ (1,537 ) $ (943 ) $ (3,574 ) $ (3,973 ) Interest income (expense) BioLargo corporate $ (3 ) $ (6 ) $ (43 ) $ (18 ) ONM Environmental (1 ) — (5 ) — Clyra Medical (8 ) (8 ) (25 ) (24 ) Water — — 1 — Total $ (12 ) $ (14 ) $ (72 ) $ (42 ) As of September 30, 2023 BioLargo ONM Clyra BLEST Water BETI Elimination Total Tangible assets $ 579 $ 3,300 $ 1,202 $ 480 $ 89 $ 144 $ (41 ) $ 5,753 Right of use leased asset 72 — — 705 — — — 777 Investment in South Korean joint venture 15 — — — — — — 15 Total $ 666 $ 3,300 $ 1,202 $ 1,185 $ 89 $ 144 $ (41 ) $ 6,545 As of December 31, 2022 BioLargo ONM Clyra BLEST Water Elimination Total Tangible assets $ 669 $ 2,064 $ 631 $ 441 $ 194 $ (41 ) $ 3,958 Right of use 136 — — 731 — — 867 Investment in South Korean joint venture 33 — — — — — 33 Total $ 838 $ 2,064 $ 631 $ 1,172 $ 194 $ (41 ) $ 4,858

Note 12 - Commitments and Conti

Note 12 - Commitments and Contingencies	9 Months Ended
Note 12 - Commitments and Contingencies	Sep. 30, 2023
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	Note 12. Office Leases We have long-term operating leases for office, industrial and laboratory space in Westminster, California, Oak Ridge, Tennessee, and Alberta, Canada. Payments made under operating leases are charged to the Consolidated Statement of Operations and Comprehensive Loss on a straight-line basis over the term of the operating lease agreement. Short-term leases less than one not three nine September 30, 2023 $254,000; three nine September 30, 2022 August 2024. not four four not September 2022, ten one None no not no

Note 13 - Subsequent Events

Note 13 - Subsequent Events	9 Months Ended
Note 13 - Subsequent Events	Sep. 30, 2023
Notes to Financial Statements
Subsequent Events [Text Block]	Note 13. Management has evaluated subsequent events through the date of the filing of this quarterly report and management noted the following for disclosure. Lincoln Park Capital Purchase of Shares From October 1, 2023, November 13, 2023, 2022 3 1 333 268973

Significant Accounting Policies

Significant Accounting Policies (Policies)	9 Months Ended
Significant Accounting Policies (Policies)	Sep. 30, 2023
Accounting Policies [Abstract]
Consolidation, Policy [Policy Text Block]	Principles of Consolidation The consolidated financial statements include the accounts of the Company, its wholly owned subsidiaries, and partially owned subsidiaries BETI, BLEST and Clyra Medical. All intercompany accounts and transactions have been eliminated.
Foreign Currency Transactions and Translations Policy [Policy Text Block]	Foreign Currency The Company has designated the functional currency of BioLargo Water, Inc., our Canadian subsidiary, to be the Canadian dollar. Therefore, translation gains and losses resulting from differences in exchange rates are recorded in accumulated other comprehensive income.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three one $250,000 not As of September 30, 2023 December 31, 2022 September 30, 2023 December 31, 2022 BioLargo, Inc. and subsidiaries $ 2,280 $ 1,681 Clyra Medical Technologies, Inc. 762 170 Total $ 3,042 $ 1,851
Receivable [Policy Text Block]	Accounts Receivable In June 2016, 2016 13, January 1, 2023 Accounts receivable are customer obligations that are unconditional. Accounts receivable are presented net of an allowance for doubtful accounts for expected credit losses, which represents an estimate of amounts that may not no not September 30, 2023 December 31, 2022
Concentration Risk, Credit Risk, Policy [Policy Text Block]	Credit Concentration We have a limited number of customers that account for significant portions of our revenue. During the three nine September 30, 2023 2022 10% Three Months Nine Months September 30, 2023 September 30, 2022 September 30, 2023 September 30, 2022 Customer A 74% 4% 76% 44% Customer B <10% <10% <10% 14% Customer C <10% <10% <10% <10% At September 30, 2023 December 31, 2022 September 30, 2023 December 31, 2022 Customer A 67 % 11 % Customer B <10% 31 % Customer D <10% 15 %
Inventory, Policy [Policy Text Block]	Inventory Inventories are stated at the lower of cost or net realizable value using the average cost method. The allowance for obsolete inventory as of September 30, 2023 December 31, 2022 September 30, 2023 December 31, 2022 Raw material $ 78 $ 46 Finished goods 44 74 Total $ 122 $ 120
Other Assets, Policy [Policy Text Block]	Other Non-Current Assets Other non-current assets consisted of (i) security deposits related to our business offices, (ii) three October 22, 2021, September 30, 2023 December 31, 2022 Patents $ 34 $ 34 Security deposits 35 35 Tax credit receivable — 55 Total $ 69 $ 124
Equity Method Investments [Policy Text Block]	Equity Method of Accounting On March 20, 2020, We account for our investment in the joint venture under the equity method of accounting. We have determined that while we have significant influence over the joint venture through our technology license and our position on the Board of Directors, we do not three nine September 30, 2023 2022,
Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]	Impairment Long-lived and definite lived intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not three nine September 30, 2023 2022
Earnings Per Share, Policy [Policy Text Block]	Earnings (Loss) Per Share We report basic and diluted earnings (loss) per share (“EPS”) for common and common share equivalents. Basic EPS is computed by dividing reported earnings by the weighted average shares outstanding. Diluted EPS is computed by adding to the weighted average shares the dilutive effect if convertible notes payable, stock options and warrants were exercised into common stock. For the three nine September 30, 2023 2022
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and revenues and expenses during the period reported. Actual results could differ from those estimates. Estimates are used when accounting for stock-based transactions, debt transactions, derivative liabilities, allowance for bad debt, asset depreciation and amortization, impairment expense, among others. The methods, estimates and judgments we use in applying these most critical accounting policies have a significant impact on the results of our financial statements.
Share-Based Payment Arrangement [Policy Text Block]	Share-Based Compensation Expense We recognize compensation expense for stock option awards on a straight-line basis over the applicable service period of the award, which is the vesting period. Fair value is determined on the grant date. Share-based compensation expense is based on the grant date fair value estimated using the Black-Scholes Option Pricing Model. For stock and stock options issued to consultants and other non-employees for services, the Company measures and records an expense as of the earlier of the date at which either: a commitment for performance by the non-employee has been reached or the non-employee’s performance is complete. The equity instruments are measured at the current fair value, and for stock options, the instruments are measured at fair value using the Black Scholes option model. The following methodology and assumptions were used to calculate share-based compensation for the nine September 30, 2023 2022 2023 2022 Non Plan 2018 Plan Non Plan 2018 Plan Risk free interest rate 4.15 % 3.48 - 4.15 % 2.32 - 3.83 % 2.32 - 3.83 % Expected volatility 112 % 112 - 114 % 115 - 117 % 115 - 117 % Expected dividend yield — — — — Forfeiture rate — — — — Life in years 10 10 10 10 Expected price volatility is the measure by which our stock price is expected to fluctuate during the expected term of an option. The expected volatility is derived from the historical daily change in the market price of our common stock, as we believe that historical volatility is the best indicator of future volatility. The risk-free interest rate used in the Black-Scholes calculation is based on the prevailing U.S. Treasury yield as determined by the U.S. Federal Reserve. We have never paid any cash dividends on our common stock and do not
Warrant Policy [Policy Text Block]	Warrants Warrants issued with our convertible and non-convertible debt instruments are accounted for under the fair value and relative fair value method. The warrant is first not. not not
Non Cash Transactions [Policy Text Block]	Non-Cash Transactions We determine the value assigned to each intangible we acquire, and/or services or products received for non-cash consideration of our common stock based on the market price of our common stock issued as consideration, at the date of the agreement of each transaction or when the service is rendered or product is received.
Revenue from Contract with Customer [Policy Text Block]	Revenue Recognition We account for revenue in accordance with ASC 606, Step 1: Step 2: Step 3: Step 4: Step 5: The Company’s products are sold through a contract with the customer and a written purchase order, in which the details of the contract are defined including the transaction price and method of shipment. The only performance obligation is to create and ship the product, and each product has separate pricing. Revenue is recognized at a point in time when the goods are shipped if the agreement is FOB manufacturer, and when goods are delivered if FOB destination. Revenue is recognized with a reduction for sales discounts, as appropriate and negotiated in the customer’s purchase order. Service contracts are performed through a written contract, which specifies the performance obligations and the rate at which the services will be billed, typically by time and materials. Each service is separately negotiated and priced. Revenue is recognized as services are performed and completed, or, for services related to product installations, at the completion of the installation. A few contracts have called for milestone or fixed cost payments, where we invoice an agreed-to amount per month for the life of the contract. In these instances, completed work, billed hourly, is recognized as revenue. If the billing amount is greater or lesser than the completed work, a receivable or payable is created. These accounts are adjusted upon additional billings as the work is completed. To date, there have been no The Company has outstanding contract liability obligations of $2,000 as of September 30, 2023 nine September 30, 2023 September 30, 2023 As we generate revenues from royalties or license fees from our intellectual property, a licensee will pay a license fee in one third
Government Grants [Policy Text Block]	Government Grants We have been awarded multiple research grants from the private and public Canadian research programs. The income we receive directly from grants is recorded as other income. We have been awarded over 80 first 2015. third third six eighteen not The grants typically provide for (i) recurring monthly amounts, (ii) reimbursement of costs for research talent for which we invoice to request payment, and (iii) ancillary cost reimbursement for research talent travel related costs. All awarded grants have specific requirements on how the money is spent, typically to employ researchers. None may Not no
Income Tax, Policy [Policy Text Block]	Income Taxes The asset and liability approach is used to recognize deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the carrying amounts and the tax bases of asset and liabilities. Deferred tax assets and liabilities are determined based on the differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The effect on deferred tax asset and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. We account for uncertainties in income tax law under a comprehensive model for the financial statement recognition, measurement, presentation, and disclosure of uncertain tax positions taken or expected to be taken in income tax returns as prescribed by generally accepted accounting principles (“GAAP”). Under GAAP, the tax effects of a position are recognized only if it is “more-likely-than- not” not not” no September 30, 2023 December 31, 2022 The Company assessed its earnings history, trends and estimates of future earnings and determined that the deferred tax asset could not September 30, 2023 December 31, 2022 100% The Company recognizes interest and penalties on income taxes as a component of income tax expense, should such an expense be realized.
Fair Value of Financial Instruments, Policy [Policy Text Block]	Fair Value of Financial Instruments Management believes the carrying amounts of the Company’s financial instruments as of September 30, 2023 December 31, 2022
Tax Credits [Policy Text Block]	Tax Credits Our research and development activities in Canada may not During the three September 30, 2023,
Lessee, Leases [Policy Text Block]	Leases At inception of a lease contract, we assess whether the contract is, or contains, a lease. Our assessment is based on: ( 1 2 3 not no September 30, 2023 nine not not 12 not As of September 30, 2023
Property, Plant and Equipment, Policy [Policy Text Block]	Property and Equipment Property and equipment includes machinery and leasehold improvements and is stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which range from 3 - 5 years or the remaining lease term. Newly built leaseholds, additions, renewals, and betterments that significantly extend the life of the asset are capitalized. The Company is currently constructing a facility and purchasing equipment for producing sodium sulfur batteries. Expenditures for repairs and maintenance are charged to expense as incurred. For assets sold or otherwise disposed of, the cost and related accumulated depreciation and amortization are removed from the accounts, and any related gain or loss is reflected in income for the period.
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements Currently there are no

Note 2 - Summary of Significa_2

Note 2 - Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2023
Notes Tables
Schedule of Cash and Cash Equivalents [Table Text Block]	September 30, 2023 December 31, 2022 BioLargo, Inc. and subsidiaries $ 2,280 $ 1,681 Clyra Medical Technologies, Inc. 762 170 Total $ 3,042 $ 1,851
Schedules of Concentration of Risk, by Risk Factor [Table Text Block]	Three Months Nine Months September 30, 2023 September 30, 2022 September 30, 2023 September 30, 2022 Customer A 74% 4% 76% 44% Customer B <10% <10% <10% 14% Customer C <10% <10% <10% <10% September 30, 2023 December 31, 2022 Customer A 67 % 11 % Customer B <10% 31 % Customer D <10% 15 %
Schedule of Inventory, Current [Table Text Block]	September 30, 2023 December 31, 2022 Raw material $ 78 $ 46 Finished goods 44 74 Total $ 122 $ 120
Schedule of Other Assets, Noncurrent [Table Text Block]	September 30, 2023 December 31, 2022 Patents $ 34 $ 34 Security deposits 35 35 Tax credit receivable — 55 Total $ 69 $ 124
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	2023 2022 Non Plan 2018 Plan Non Plan 2018 Plan Risk free interest rate 4.15 % 3.48 - 4.15 % 2.32 - 3.83 % 2.32 - 3.83 % Expected volatility 112 % 112 - 114 % 115 - 117 % 115 - 117 % Expected dividend yield — — — — Forfeiture rate — — — — Life in years 10 10 10 10

Note 4 - Debt Obligations (Tabl

Note 4 - Debt Obligations (Tables)	9 Months Ended
Note 4 - Debt Obligations (Tables)	Sep. 30, 2023
Notes Tables
Schedule of Debt [Table Text Block]	September 30, 2023 December 31, 2022 Current portion of debt: SBA Paycheck Protection Program loan $ 43 $ 43 Vehicle loan, current portion 13 — Convertible note payable, matures March 1, 2023 — 50 SBA EIDL Loan, matures July 2050, current portion 10 10 Debt discount, net of amortization — (3 ) Total current portion of debt $ 66 $ 100 Long-term debt: SBA Paycheck Protection Program loans, matures May 2025 $ 97 $ 97 Vehicle loan, matures March 2029 58 — SBA EIDL Loan, matures July 2050 138 140 Total long-term debt, net of current $ 293 $ 237 Total $ 359 $ 337

Note 5 - Share-based Compensa_2

Note 5 - Share-based Compensation (Tables)	9 Months Ended
Note 5 - Share-based Compensation (Tables)	Sep. 30, 2023
Notes Tables
Share-Based Payment Arrangement, Option, Activity [Table Text Block]	Options Outstanding Exercise Price per share Weighted Average Price per share Aggregate intrinsic Value(1) Balance, December 31, 2022 28,484,549 $ 0.12 – 0.43 $ 0.19 Granted 8,219,920 0.17 – 0.20 $ 0.18 Balance, September 30, 2023 36,704,469 0.12 – 0.43 $ 0.19 Unvested (4,648,922 ) 0.12 – 0.27 $ 0.15 Vested, September 30, 2023 32,055,547 0.12 – 0.43 $ 0.19 $ 278,000 Balance, December 31, 2021 23,186,142 0.16 – 0.43 $ 0.19 Granted 4,748,212 0.18 – 0.27 $ 0.22 Balance, September 30, 2022 27,934,354 0.12 – 0.43 $ 0.19 Options Outstanding Exercise price per share Weighted Average Price per share Aggregate intrinsic Value(1) Balance, December 31, 2022 1,904,085 $ 0.28 – 0.69 $ 0.56 Expired (340,000 ) 0.28 0.30 0.30 Balance, September 30, 2023 1,564,085 0.28 – 0.69 $ 0.61 $ — Balance, December 31, 2021 2,879,246 0.23 – 0.94 $ 0.49 Expired (975,161 ) 0.28 0.36 Balance, September 30, 2022 1,904,085 $ 0.24 – 0.94 $ 0.56 Non-plan Options outstanding Exercise price per share Weighted averageprice per share Aggregate intrinsic Value(1) Balance, December 31, 2022 19,023,829 $ 0.12 – 0.83 $ 0.39 Granted 60,040 0.18 – 0.20 0.20 Expired (1,205,550 ) 0.30 0.30 Balance, September 30, 2023 17,878,319 $ 0.12 – 0.83 $ 0.39 Unvested (507,500 ) 0.45 0.45 Vested, September 30, 2023 17,370,819 $ 0.12 – 0.83 $ 0.39 $ 28,000 Balance, December 31, 2021 20,119,207 $ 0.17 – 1.00 $ 0.41 Granted 105,797 0.23 - 0.27 0.26 Balance, September 30, 2022 20,225,004 $ 0.17 – 1.00 $ 0.39

Note 6 - Warrants (Tables)

Note 6 - Warrants (Tables)	9 Months Ended
Note 6 - Warrants (Tables)	Sep. 30, 2023
Notes Tables
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]	Warrants outstanding Exercise price per share Weighted average price per share Aggregate intrinsic value(1) Balance, December 31, 2022 49,023,398 $ 0.13 – 1.00 $ 0.26 Granted 10,669,896 0.21 – 0.29 0.26 Expired (11,313,584 ) 0.10 - 0.48 0.23 Balance, September 30, 2023 48,379,710 $ 0.13 – 1.00 $ 0.27 $ 18,000 Balance, December 31, 2021 36,765,502 $ 0.16 – 1.00 $ 0.27 Granted 27,137,048 0.20 – 0.29 0.23 Expired (10,273,722 ) 0.19 – 0.48 0.25 Balance, September 30, 2022 53,628,828 $ 0.14 – 1.00 $ 0.26
Schedule Of Assumptions Used To Determine Fair Value Of Warrants [Table Text Block]	2023 2022 Risk free interest rate 3.88 – 4.27 % 3.69 – 3.88 % Expected volatility 40 – 95 % 40 % Expected dividend yield — — Forfeiture rate — — Expected life in years .5 – 5 3

Note 7 - Accounts Payable and_2

Note 7 - Accounts Payable and Accrued Expenses (Tables)	9 Months Ended
Note 7 - Accounts Payable and Accrued Expenses (Tables)	Sep. 30, 2023
Notes Tables
Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]	Category BioLargo ONM BLEST Water BETI Intercompany amounts Totals Accounts payable $ 208 $ 417 $ 5 $ 91 $ 31 $ (82 ) $ 670 Accrued payroll 40 85 69 — — — 194 Accrued interest 25 — — — — — 25 Total $ 889 Category BioLargo ONM BLEST Water Intercompany amounts Totals Accounts payable $ 187 $ 486 $ 7 $ 119 $ (82 ) $ 717 Accrued payroll 20 58 120 — — 198 Accrued interest 25 — — — — 25 Total $ 940

Note 8 - Noncontrolling Inter_2

Note 8 - Noncontrolling Interest - Clyra Medical (Tables)	9 Months Ended
Note 8 - Noncontrolling Interest - Clyra Medical (Tables)	Sep. 30, 2023
Notes Tables
Schedule of Other Ownership Interests [Table Text Block]	Clyra Options Outstanding Exercise price per share Weighted average price per share Balance, December 31, 2022 15,833 $ 1.00 – 310 $ 5.53 Exercised (2,964 ) $ 1.00 $ 1.00 Granted 1,215 1.00 – 271 171.99 Balance, September 30, 2023 14,084 $ 1.00 – 310 $ 20.85 Balance, December 31, 2021 14,004 $ 1.00 $ 1.00 Granted 1,403 1.00 1.00 Balance, September 30, 2022 15,407 $ 1.00 $ 1.00
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	2023 2022 Non Plan 2018 Plan Non Plan 2018 Plan Risk free interest rate 4.15 % 3.48 - 4.15 % 2.32 - 3.83 % 2.32 - 3.83 % Expected volatility 112 % 112 - 114 % 115 - 117 % 115 - 117 % Expected dividend yield — — — — Forfeiture rate — — — — Life in years 10 10 10 10
Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]	Category BioLargo ONM BLEST Water BETI Intercompany amounts Totals Accounts payable $ 208 $ 417 $ 5 $ 91 $ 31 $ (82 ) $ 670 Accrued payroll 40 85 69 — — — 194 Accrued interest 25 — — — — — 25 Total $ 889 Category BioLargo ONM BLEST Water Intercompany amounts Totals Accounts payable $ 187 $ 486 $ 7 $ 119 $ (82 ) $ 717 Accrued payroll 20 58 120 — — 198 Accrued interest 25 — — — — 25 Total $ 940
Clyra Medical [Member]
Notes Tables
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	September 30, 2023 December 31, 2022 Risk free interest rate 3.48 – 4.15 % 2 % Expected volatility 40 – 49 % 40 % Expected dividend yield — — Forfeiture rate — — Expected life in years 10 10
Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]	Category 2023 2022 Accounts payable $ 158 $ 186 Accrued payroll 12 45 Accrued interest 8 7 Accrued dividend 152 — Total $ 330 $ 238

Note 11 - Business Segment In_2

Note 11 - Business Segment Information (Tables)	9 Months Ended
Note 11 - Business Segment Information (Tables)	Sep. 30, 2023
Notes Tables
Schedule of Segment Reporting Information, by Segment [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Revenue BioLargo corporate $ — $ 2 $ — $ 4 ONM Environmental 2,513 1,199 7,374 2,499 BLEST 843 401 1,742 1,613 BETI — — — — Water 22 1 31 1 Clyra Medical 14 17 20 34 Intersegment revenue (720 ) (120 ) (1,307 ) (365 ) Total $ 2,672 $ 1,500 $ 7,860 $ 3,786 Research and development expense BioLargo corporate $ (234 ) $ (140 ) $ (665 ) $ (570 ) ONM Environmental (14 ) — (14 ) — BLEST (433 ) (100 ) (971 ) (288 ) BETI (537 ) — (840 ) — Water (128 ) (119 ) (401 ) (446 ) Clyra Medical (68 ) (31 ) (262 ) (73 ) Intersegment R&D 720 119 1,307 359 Total $ (694 ) $ (271 ) $ (1,846 ) $ (1,018 ) Operating income (loss) BioLargo corporate $ (797 ) $ (783 ) $ (2,230 ) $ (2,925 ) ONM Environmental 969 400 2,786 418 BLEST (568 ) (179 ) (1,388 ) (158 ) BETI (559 ) — (943 ) — Water (155 ) (141 ) (549 ) (572 ) Clyra Medical (427 ) (240 ) (1,250 ) (736 ) Total $ (1,537 ) $ (943 ) $ (3,574 ) $ (3,973 ) Interest income (expense) BioLargo corporate $ (3 ) $ (6 ) $ (43 ) $ (18 ) ONM Environmental (1 ) — (5 ) — Clyra Medical (8 ) (8 ) (25 ) (24 ) Water — — 1 — Total $ (12 ) $ (14 ) $ (72 ) $ (42 ) As of September 30, 2023 BioLargo ONM Clyra BLEST Water BETI Elimination Total Tangible assets $ 579 $ 3,300 $ 1,202 $ 480 $ 89 $ 144 $ (41 ) $ 5,753 Right of use leased asset 72 — — 705 — — — 777 Investment in South Korean joint venture 15 — — — — — — 15 Total $ 666 $ 3,300 $ 1,202 $ 1,185 $ 89 $ 144 $ (41 ) $ 6,545 As of December 31, 2022 BioLargo ONM Clyra BLEST Water Elimination Total Tangible assets $ 669 $ 2,064 $ 631 $ 441 $ 194 $ (41 ) $ 3,958 Right of use 136 — — 731 — — 867 Investment in South Korean joint venture 33 — — — — — 33 Total $ 838 $ 2,064 $ 631 $ 1,172 $ 194 $ (41 ) $ 4,858

Note 1 - Business and Organiz_2

Note 1 - Business and Organization (Details Textual)	3 Months Ended						9 Months Ended
Note 1 - Business and Organization (Details Textual)	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2017
Number of Wholly-Owned Subsidiaries	6						6
Revenue from Contract with Customer, Including Assessed Tax	$ 2,672,000			$ 1,500,000			$ 7,860,000	$ 3,786,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(1,508,000)	$ (1,626,000)	$ (494,000)	(847,000)	$ (1,333,000)	$ (1,544,000)	(3,628,000)	(3,724,000)
Net Cash Provided by (Used in) Operating Activities							(2,363,000)	$ (2,803,000)
Working Capital (Deficit)	2,951,000						2,951,000
Assets, Current	4,691,000						4,691,000		$ 3,153,000
Stock Issued During Period, Value, New Issues	203,000	494,000	800,000	$ 1,117,000	$ 948,000	$ 1,202,000
Cash and Cash Equivalents, at Carrying Value	3,042,000						3,042,000		$ 1,851,000
Vehicle Loan [Member]
Long-Term Debt	71,000						71,000
SBA CARES Act Paycheck Protection Program [Member]
Long-Term Debt	140,000						140,000
Economic Injury Disaster Loan [Member]
Long-Term Debt	148,000						148,000
Inventory Line of Credit [Member] \| Clyra Medical Technologies [Member]
Long-Term Line of Credit	$ 234,000						234,000
The 2020 Unit Offering [Member]
Stock Issued During Period, Value, New Issues							995,000
Lincoln Park Capital Fund, LLC [Member]
Stock Issued During Period, Value, New Issues							$ 502,000
Clyra Medical Technologies [Member]
Subsidiary, Ownership Percentage, Parent	53%						53%
Noncontrolling Interest, Increase from Subsidiary Equity Issuance	$ 288,000	$ 1,062,000	225,000				$ 1,575,000
BioLargo Engineering, Science & Technologies, LLC [Member]
Subsidiary, Ownership Percentage, Parent										100%
BioLargo Engineering, Science & Technologies, LLC [Member] \| Approximation [Member]
Subsidiary, Ownership Percentage, Parent	82%						82%
BioLargo Energy Technologies, Inc (BETI) [Member]
Subsidiary, Ownership Percentage, Parent	96%						96%
Noncontrolling Interest, Increase from Subsidiary Equity Issuance			$ 550,000				$ 905,000

Note 2 - Summary of Significa_3

Note 2 - Summary of Significant Accounting Policies (Details Textual)		3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 20, 2020 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Oct. 22, 2021 USD ($)
Accounts Receivable, Allowance for Credit Loss, Current		$ 113,000		$ 113,000		$ 12,000
Inventory Valuation Reserves		212,000		212,000		158,000
Income (Loss) from Equity Method Investments				(18,000)	$ (15,000)
Impairment of Intangible Assets (Excluding Goodwill)		0	$ 0	0	0
Contract with Customer, Liability		2,000		2,000
Contract with Customer, Liability, Revenue Recognized				15,000
Customer Deposit Liability, Current		122,000		122,000		184,000
Unrecognized Tax Benefits, Ending Balance		$ 0		$ 0		0
Operating Lease, Weighted Average Remaining Lease Term (Year)		9 years		9 years
Operating Lease, Weighted Average Discount Rate, Percent		18%		18%
Operating Lease, Right-of-Use Asset		$ 777,000		$ 777,000		$ 867,000
Operating Lease, Liability		792,000		$ 792,000
Clyra Medical Technologies [Member]
Employee Retention Tax Credits Received		$ 41,000
Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)		3 years		3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)		5 years		5 years
Canadian Government Grants [Member] \| Minimum [Member]
Grant Term (Month)				6 months
Canadian Government Grants [Member] \| Maximum [Member]
Grant Term (Month)				18 months
CANADA
Customer Deposit Liability, Current		$ 111,000		$ 111,000
Odin Co Ltd [Member]
Payments to Acquire Interest in Joint Venture	$ 100,000
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	40%			40%
Income (Loss) from Equity Method Investments		$ (6,000)	$ (15,000)	$ (18,000)	$ (23,000)
Odin Co Ltd [Member] \| Tomorrow Water [Member]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	30%
Odin Co Ltd [Member] \| BKT and Tomorrow Water [Member]
Payments to Acquire Interest in Joint Venture	$ 150,000
Patents [Member]
Intangible Assets, Net (Excluding Goodwill), Total							$ 34,000
Customer Concentration Risk [Member] \| Accounts Receivable [Member]
Number of Major Customers				1		3
Customer Concentration Risk [Member] \| Accounts Receivable [Member] \| One Customer [Member]
Concentration Risk, Percentage				10%
Customer Concentration Risk [Member] \| Accounts Receivable [Member] \| Three Customers [Member]
Concentration Risk, Percentage						10%

Note 2 - Summary of Significa_4

Note 2 - Summary of Significant Accounting Policies - Summary of Cash Balances (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Cash and Cash Equivalents, at Carrying Value	$ 3,042,000	$ 1,851,000
Parent Company [Member]
Cash and Cash Equivalents, at Carrying Value	2,280,000	1,681,000
Noncontrolling Interest [Member]
Cash and Cash Equivalents, at Carrying Value	$ 762,000	$ 170,000

Note 2 - Summary of Significa_5

Note 2 - Summary of Significant Accounting Policies - Credit Concentration (Details) - Customer Concentration Risk [Member]	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Customer A [Member] \| Revenue from Contract with Customer Benchmark [Member]
Credit concentration	74%	4%	76%	44%
Customer A [Member] \| Accounts Receivable [Member]
Credit concentration			67%	11%
Customer B [Member] \| Revenue from Contract with Customer Benchmark [Member]
Credit concentration	10%	10%	10%	14%
Customer B [Member] \| Accounts Receivable [Member]
Credit concentration			10%	31%
Customer C [Member] \| Revenue from Contract with Customer Benchmark [Member]
Credit concentration	10%	10%	10%	10%
Customer D [Member] \| Accounts Receivable [Member]
Credit concentration			10%	15%

Note 2 - Summary of Significa_6

Note 2 - Summary of Significant Accounting Policies - Inventory (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Raw material	$ 78	$ 46
Finished goods	44	74
Total	$ 122	$ 118

Note 2 - Summary of Significa_7

Note 2 - Summary of Significant Accounting Policies - Other Non-current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Patents	$ 34	$ 34
Security deposits	35	35
Tax credit receivable		55
Total	$ 69	$ 124

Note 2 - Summary of Significa_8

Note 2 - Summary of Significant Accounting Policies - Stock Options, Valuation Assumptions (Details)	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Non Plan [Member]
Risk free interest rate	4.15%
Expected volatility	112%
Expected dividend yield	0%
Forfeiture rate	0%
Expected life in years (Year)	10 years
Non Plan [Member] \| Minimum [Member]
Risk free interest rate	2.32%
Expected volatility	115%
Non Plan [Member] \| Maximum [Member]
Risk free interest rate		3.83%
Expected volatility		117%
2018 Equity Incentive Plan [Member]
Expected dividend yield	0%	0%
Forfeiture rate	0%	0%
Expected life in years (Year)	10 years	10 years
2018 Equity Incentive Plan [Member] \| Minimum [Member]
Risk free interest rate	3.48%	2.32%
Expected volatility	112%	115%
2018 Equity Incentive Plan [Member] \| Maximum [Member]
Risk free interest rate	4.15%	3.83%
Expected volatility	114%	117%

Note 3 - Sale of Stock for Ca_2

Note 3 - Sale of Stock for Cash (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
Note 3 - Sale of Stock for Cash (Details Textual) - USD ($)	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Proceeds from Issuance of Common Stock			$ 1,497,000	$ 3,267,000
Warrants Issued with 2020 Unit Offering [Member] \| Minimum [Member]
Warrants and Rights Outstanding, Term (Month)	6 months	6 months	6 months	6 months
Warrants Issued with 2020 Unit Offering [Member] \| Maximum [Member]
Warrants and Rights Outstanding, Term (Month)	5 years	5 years	5 years	5 years
The 2020 Unit Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)	0	3,766,126	5,234,948	13,568,524
Proceeds from Issuance of Common Stock		$ 632,000	$ 995,000	$ 2,364,000
Lincoln Park Capital Fund, LLC [Member]
Stock Purchase Agreement, Maximum Amount of Common Stock					$ 10,000,000
Stock Issued During Period, Shares, New Issues (in shares)	1,190,223	2,440,958	2,833,846	4,353,919
Proceeds from Issuance of Common Stock	$ 203,000	$ 485,000	$ 502,000	$ 903,000

Note 4 - Debt Obligations (Deta

Note 4 - Debt Obligations (Details Textual) - USD ($)					3 Months Ended		4 Months Ended	9 Months Ended
Note 4 - Debt Obligations (Details Textual) - USD ($)	Mar. 06, 2023	Feb. 07, 2023	May 12, 2022	Feb. 07, 2022	Sep. 30, 2023	Sep. 30, 2022	Jul. 31, 2020	Sep. 30, 2023	Sep. 30, 2022
Interest Expense, Debt					$ 12,000	$ 14,000		$ 72,000	$ 42,000
Paycheck Protection Program CARES Act [Member] \| ONM [Member]
Extinguishment of Debt, Amount				$ 174,000
Proceeds from Issuance of Debt				$ 217,000
Long-Term Debt					43,000			43,000
Paycheck Protection Program CARES Act [Member] \| BELST [Member]
Proceeds from Issuance of Debt			$ 97,000
Economic Injury Disaster Loan [Member]
Long-Term Debt					$ 148,000			$ 148,000
Economic Injury Disaster Loan [Member] \| ONM [Member]
Debt Instrument, Face Amount							$ 150,000
Debt Instrument, Interest Rate, Stated Percentage							3.75%
Debt Instrument, Periodic Payment							$ 731
Warrant Issued With Conversion of Note [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	200,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.21
Warrants and Rights Outstanding, Term (Month)	5 years
Conversion of Note into BETI Common Shares [Member]
Debt Conversion, Original Debt, Amount	$ 50,000
Vehicle Loan [Member]
Debt Instrument, Face Amount		$ 80,000
Debt Instrument, Interest Rate, Stated Percentage		5.29%
Debt Instrument, Periodic Payment		$ 1,000

Note 4 - Debt Obligations - Sch

Note 4 - Debt Obligations - Schedule of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Long-term debt, current	$ 66	$ 100
Debt discount, net of amortization	0	(3)
Total current portion of debt	66	100
Total long-term debt, net of current	293	237
Total	359	337
Vehicle Loan [Member]
Long-term debt, current	13	0
Total long-term debt, net of current	58	0
Paycheck Protection Program CARES Act [Member]
SBA Paycheck Protection Program loan	43	43
SBA Paycheck Protection Program loans, matures May 2025	97	97
Convertible Note, Maturing On March 1, 2023 [Member]
Convertible notes	0	50
Economic Injury Disaster Loan [Member]
Long-term debt, current	10	10
Total long-term debt, net of current	$ 138	$ 140

Note 5 - Share-based Compensa_3

Note 5 - Share-based Compensation (Details Textual) - USD ($)										3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Mar. 22, 2022	Jun. 22, 2018	Sep. 07, 2017	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Stock Issued During Period, Value, Issued for Services										$ 37,000	$ 75,000	$ 207,000	$ 96,000	$ 59,000	$ 17,000
Share Price (in dollars per share)	$ 0.17									$ 0.17						$ 0.17
2018 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)								10 years
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)	50,000,000							40,000,000		50,000,000						50,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Per Year (in shares)								2,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)																8,219,920	4,748,212
The 2007 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)									10 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Expirations in Period (in shares)																340,000	975,161
Non Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)																60,040	105,797
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)																$ 0.2	$ 0.26
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Expirations in Period (in shares)																1,205,550
Share-Based Payment Arrangement, Option [Member] \| Clyra Medical Technologies [Member]
Share-Based Payment Arrangement, Expense										$ 45,000			85,000			$ 172,000	$ 308,000
Selling, General and Administrative Expenses [Member]
Share-Based Payment Arrangement, Expense										$ 725,000			$ 338,000			$ 1,269,000	$ 1,455,000
Officer [Member]
Stock Issued During Period, Value, Issued for Services	$ 12,000	$ 12,000	$ 6,000	$ 72,000
Stock Issued During Period, Shares, Issued for Services (in shares)	69,563	68,541	30,747	167,781
Shares Issued, Price Per Share (in dollars per share)	$ 0.17	$ 0.18	$ 0.2	$ 0.27						$ 0.17	$ 0.18	$ 0.2	$ 0.27			$ 0.17	$ 0.27
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Minimum Cash Amount Receipt																$ 3,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Minimum Revenue Required																$ 3,000,000
Consultants [Member]
Stock Issued During Period, Value, Issued for Services	$ 25,000	$ 63,000	$ 201,000	$ 24,000	$ 60,000	$ 31,000
Stock Issued During Period, Shares, Issued for Services (in shares)	146,123	352,370	899,743	211,047	76,996	86,752
Shares Issued, Price Per Share (in dollars per share)	$ 0.17	$ 0.18	$ 0.2	$ 0.27	$ 0.18	$ 0.23				$ 0.17	$ 0.18	$ 0.2	$ 0.27	$ 0.18	$ 0.23	$ 0.17	$ 0.27
Consultants [Member] \| 2018 Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)																4,069,922	682,991
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value																$ 657,000	$ 145,000
Officer, Board of Directors, Employees, and a Consultant [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)																8,219,920	4,748,212
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value																$ 1,370,000
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)	$ 0.17	$ 0.18	$ 0.2
Board Of Directors [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)																1,565,858	1,134,356
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value																$ 266,000	$ 246,000
Board Of Directors [Member] \| Minimum [Member]
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)																	$ 0.18
Board Of Directors [Member] \| Maximum [Member]
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)																	$ 0.27
Employees [Member] \| Employee Retention Program [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)																1,784,140	2,340,730
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value																$ 306,000	$ 492,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)																4 years	4 years
Employees [Member] \| Employee Retention Program [Member] \| Minimum [Member]
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)																	$ 0.18
Employees [Member] \| Employee Retention Program [Member] \| Maximum [Member]
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)																	$ 0.27
Chief Financial Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value																	$ 0.22
Chief Financial Officer [Member] \| 2018 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)							10 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)							300,000									800,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value																$ 141,000
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)							$ 0.2
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Expirations in Period (in shares)																500,000
Term Extension (Year)							1 year
Share-based Compensation Arrangement By Share-based Payment Award, Options Grants Per Month, Gross (in shares)							25,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested, Number of Shares (in shares)							25,000
CFO and President [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value																	$ 290,135
President [Member]
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)																	$ 0.23
Vendors [Member] \| Non Plan [Member]
Share-Based Payment Arrangement, Expense																$ 11,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)																60,040	105,797
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value																	$ 36,000
Vendors [Member] \| Non Plan [Member] \| Minimum [Member]
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)																$ 0.18	$ 0.23
Vendors [Member] \| Non Plan [Member] \| Maximum [Member]
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)																$ 0.2	$ 0.27

Note 5 - Share-based Compensa_4

Note 5 - Share-based Compensation - Stock Options (Details) - USD ($)		9 Months Ended		12 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
2018 Equity Incentive Plan [Member]
Options outstanding, balance (in shares)		28,484,549	23,186,142	23,186,142
Options granted (in shares)		8,219,920	4,748,212
Options Unvested (in shares)		(4,648,922)
Options Vested (in shares)		32,055,547
Vested, September 30, 2023	[1]	$ 278,000
Options outstanding, balance (in shares)		36,704,469	27,934,354	28,484,549
2018 Equity Incentive Plan [Member] \| Minimum [Member]
Exercise price per share, balance (in dollars per share)		$ 0.12	$ 0.16	$ 0.16
Exercise price per share, granted (in dollars per share)		0.17	0.18
Exercise price per share, Unvested (in dollars per share)		0.12
Exercise price per share, Vested (in dollars per share)		0.12
Exercise price per share, balance (in dollars per share)		0.12	0.12	0.12
2018 Equity Incentive Plan [Member] \| Maximum [Member]
Exercise price per share, balance (in dollars per share)		0.43	0.43	0.43
Exercise price per share, granted (in dollars per share)		0.2	0.27
Exercise price per share, Unvested (in dollars per share)		0.27
Exercise price per share, Vested (in dollars per share)		0.43
Exercise price per share, balance (in dollars per share)		0.43	0.43	0.43
2018 Equity Incentive Plan [Member] \| Weighted Average [Member]
Weighted average exercise price per share, balance (in dollars per share)		0.19	0.19	0.19
Weighted average exercise price per share, granted (in dollars per share)		0.18	0.22
Weighted average exercise price per share, unvested (in dollars per share)		0.15
Weighted average exercise price per share, vested (in dollars per share)		0.19
Weighted average exercise price per share, balance (in dollars per share)		$ 0.19	$ 0.19	$ 0.19
The 2007 Equity Incentive Plan [Member]
Options outstanding, balance (in shares)		1,904,085	2,879,246	2,879,246
Options outstanding, balance (in shares)		1,564,085	1,904,085	1,904,085
Options outstanding, Expired (in shares)		(340,000)	(975,161)
The 2007 Equity Incentive Plan [Member] \| Minimum [Member]
Weighted average exercise price per share, balance (in dollars per share)		$ 0.28	$ 0.23	$ 0.23
Weighted average exercise price per share, balance (in dollars per share)		0.28	0.24	0.28
Weighted average exercise price per share, Expired (in dollars per share)		0.28	0.28
The 2007 Equity Incentive Plan [Member] \| Maximum [Member]
Weighted average exercise price per share, balance (in dollars per share)		0.69	0.94	0.94
Weighted average exercise price per share, balance (in dollars per share)		0.69	0.94	0.69
Weighted average exercise price per share, Expired (in dollars per share)		0.3	0.35
The 2007 Equity Incentive Plan [Member] \| Weighted Average [Member]
Weighted average exercise price per share, balance (in dollars per share)		0.56	0.49	0.49
Weighted average exercise price per share, balance (in dollars per share)		0.61	0.56	$ 0.56
Weighted average exercise price per share, Expired (in dollars per share)		$ 0.3	$ 0.36
Non Plan [Member]
Options outstanding, balance (in shares)		19,023,829	20,119,207	20,119,207
Weighted average exercise price per share, balance (in dollars per share)		$ 0.39	$ 0.41	$ 0.41
Options granted (in shares)		60,040	105,797
Weighted average exercise price per share, granted (in dollars per share)		$ 0.2	$ 0.26
Options Unvested (in shares)		(507,500)
Exercise price per share, Unvested (in dollars per share)		$ 0.45
Weighted average exercise price per share, unvested (in dollars per share)		$ 0.45
Options Vested (in shares)		17,370,819
Weighted average exercise price per share, vested (in dollars per share)		$ 0.39
Vested, September 30, 2023	[1]	$ 28,000
Options outstanding, balance (in shares)		17,878,319	20,225,004	19,023,829
Weighted average exercise price per share, balance (in dollars per share)		$ 0.39	$ 0.39	$ 0.39
Options outstanding, Expired (in shares)		(1,205,550)
Weighted average exercise price per share, Expired (in dollars per share)		$ 0.3
Exercise price per share, Expired (in dollars per share)		0.3
Non Plan [Member] \| Minimum [Member]
Exercise price per share, balance (in dollars per share)		0.12	0.17	0.17
Exercise price per share, granted (in dollars per share)		0.18	0.23
Exercise price per share, Vested (in dollars per share)		0.12
Exercise price per share, balance (in dollars per share)		0.12	0.17	0.12
Non Plan [Member] \| Maximum [Member]
Exercise price per share, balance (in dollars per share)		0.83	1	1
Exercise price per share, granted (in dollars per share)		0.2	0.27
Exercise price per share, Vested (in dollars per share)		0.83
Exercise price per share, balance (in dollars per share)		$ 0.83	$ 1	$ 0.83

[1]Aggregate intrinsic value based on closing common stock price of $0.17 at September 30, 2023.

Note 6 - Warrants (Details Text

Note 6 - Warrants (Details Textual) - USD ($)		Sep. 30, 2023	Mar. 06, 2023	Sep. 30, 2022
Share Price (in dollars per share)		$ 0.17
Warrants and Rights Outstanding	[1]	$ 18,000
Note Payable, Maturing March 8, 2023 [Member]
Debt Instrument, Face Amount			$ 50,000
Six-month Warrants in Connection With the 2020 Unit Offering [Member]
Warrants and Rights Outstanding, Term (Month)		6 months
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)		5,234,948		13,568,524
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 0.23
Six-month Warrants in Connection With the 2020 Unit Offering [Member] \| Minimum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 0.19
Six-month Warrants in Connection With the 2020 Unit Offering [Member] \| Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 0.23
Five-year Warrants in Connection With the 2020 Unit Offering [Member]
Warrants and Rights Outstanding, Term (Month)		5 years		5 years
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)		5,234,948		13,568,524
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 0.29
Warrants and Rights Outstanding		$ 913,000		$ 2,898,000
Five-year Warrants in Connection With the 2020 Unit Offering [Member] \| Minimum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 0.24
Five-year Warrants in Connection With the 2020 Unit Offering [Member] \| Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 0.33
Warrants Issued in Connection with Conversion of Interest on Note Payable Maturing March 8, 2023 [Member]
Warrants and Rights Outstanding, Term (Month)			5 years
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)			200,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)			$ 0.21
Warrants and Rights Outstanding			$ 30,000

[1]Aggregate intrinsic value based on closing common stock price of $0.17 at September 30, 2023.

Note 6 - Warrants - Warrants Ou

Note 6 - Warrants - Warrants Outstanding (Details) - $ / shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Balance, outstanding (in shares)	49,023,398	36,765,502
Granted (in shares)	10,669,896	27,137,048
Expired (in shares)	(11,313,584)	(10,273,722)
Balance, outstanding (in shares)	48,379,710	53,628,828
Minimum [Member]
Balance, outstanding, price range (in dollars per share)	$ 0.13	$ 0.16
Granted, price range (in dollars per share)	0.21	0.2
Expired, price range (in dollars per share)	0.1	0.19
Balance, outstanding, price range (in dollars per share)	0.13	0.14
Maximum [Member]
Balance, outstanding, price range (in dollars per share)	1	1
Granted, price range (in dollars per share)	0.29	0.29
Expired, price range (in dollars per share)	0.48	0.48
Balance, outstanding, price range (in dollars per share)	1	1
Weighted Average [Member]
Balance, outstanding, price range (in dollars per share)	0.26	0.27
Granted, price range (in dollars per share)	0.26	0.23
Expired, price range (in dollars per share)	0.23	0.25
Balance, outstanding, price range (in dollars per share)	$ 0.27	$ 0.26

Note 6 - Warrants - Assumptions

Note 6 - Warrants - Assumptions Used to Determine Fair Value of Warrants (Details)	Sep. 30, 2023	Sep. 30, 2022
Measurement Input, Price Volatility [Member]
Risk free interest rate		0.40
Measurement Input, Expected Term [Member]
Risk free interest rate		3
Minimum [Member] \| Measurement Input, Risk Free Interest Rate [Member]
Risk free interest rate	0.0388	0.0369
Minimum [Member] \| Measurement Input, Price Volatility [Member]
Risk free interest rate	0.40
Maximum [Member] \| Measurement Input, Risk Free Interest Rate [Member]
Risk free interest rate	0.0427	0.0388
Maximum [Member] \| Measurement Input, Price Volatility [Member]
Risk free interest rate	0.95

Note 7 - Accounts Payable and_3

Note 7 - Accounts Payable and Accrued Expenses - Summary of Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Accounts payable	$ 670	$ 717
Accrued payroll	194	198
Accrued interest	25	25
Total	889	940
Corporate, Non-Segment [Member]
Accounts payable	208	187
Accrued payroll	40	20
Accrued interest	25	25
Operating Segments [Member] \| Odor-No-More [Member]
Accounts payable	417	486
Accrued payroll	85	58
Accrued interest	0	0
Operating Segments [Member] \| BLEST [Member]
Accounts payable	5	7
Accrued payroll	69	120
Accrued interest	0	0
Operating Segments [Member] \| BioLargo Water [Member]
Accounts payable	91	119
Accrued payroll	0	0
Accrued interest	0	0
Operating Segments [Member] \| BioLargo Energy Technologies, Inc (BETI) [Member]
Accounts payable	31
Accrued payroll	0
Accrued interest	0
Consolidation, Eliminations [Member]
Accounts payable	(82)	(82)
Accrued payroll	0	0
Accrued interest	$ 0	$ 0

Note 8 - Noncontrolling Inter_3

Note 8 - Noncontrolling Interest - Clyra Medical (Details Textual) - USD ($)							1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
		Jun. 30, 2023	Jan. 09, 2023	Dec. 20, 2022	Mar. 02, 2022	Jun. 30, 2020	Jul. 31, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Apr. 08, 2022
Preferred Stock, Shares Outstanding (in shares)								0		0		0
Proceeds from Issuance of Preferred Stock and Preference Stock										$ 1,575,000	$ 100,000
Warrants and Rights Outstanding	[1]							$ 18,000		18,000
Proceeds from Stock Options Exercised										$ 3,000	$ 0
Clyra Medical [Member] \| Common Stock [Member]
Investment Owned, Balance, Shares (in shares)								51,571		51,571		51,571
Clyra Medical [Member] \| Preferred Stock, Series A [Member]
Investment Owned, Balance, Shares (in shares)								1,660		1,660		1,352
Clyra Medical [Member]
Shares, Outstanding (in shares)								99,501		99,501		91,145
Common Stock, Shares, Outstanding (in shares)								92,035		92,035		89,070
Shares Issued, Price Per Share (in dollars per share)				$ 310
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)										$ 171.99	$ 1
Proceeds from Stock Options Exercised								$ 2,964
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period (in shares)								2,964		2,964
Clyra Medical [Member] \| Vendors and Employees [Member] \| Share-Based Payment Arrangement, Option [Member]
Share-Based Payment Arrangement, Expense								$ 45,000	$ 85,000	$ 172,000	$ 308,000
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)										$ 271
Clyra Medical [Member] \| Employees and Consultants [Member] \| Share-Based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Discount Rate										30%
Clyra Medical [Member] \| Warrants Issued in Conjunction With the Sale of Series A Preferred Stock [Member]
Warrants and Rights Outstanding, Term (Month)				3 years
Warrants and Rights Outstanding				$ 410,000
Clyra Medical [Member] \| Shares Issued for Debt Owed to Biolargo [Member]
Debt Conversion, Converted Instrument, Amount					$ 633,000		$ 96,000
Debt Conversion, Converted Instrument, Shares Issued (in shares)					2,042		308
Clyra Medical [Member] \| Series A Preferred Stock [Member]
Preferred Stock, Shares Outstanding (in shares)								7,466		7,466		2,075
Stock Issued During Period, Shares, New Issues (in shares)								928		5,081
Proceeds from Issuance of Preferred Stock and Preference Stock								$ 288,000		$ 1,575,000
Shares Issued, Price Per Share (in dollars per share)				$ 372
Preferred Stock, Dividend Rate, Percentage				15%
Preferred Stock, Convertible, Sale of Stock Amount				$ 5,000,000
Clyra Medical [Member] \| Revolving Credit Facility [Member] \| Vernal Bay Capital Group, LLC [Member] \| Inventory Line of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity						$ 1,000,000
Proceeds from Lines of Credit, Total						$ 260,000
Repayments of Lines of Credit		$ 126,000
Stock Issued During Period, Shares, Commitment Fee (in shares)						322						322
Stock Issued During Period, Value, Commitment Fee						$ 70,000
Debt Instrument, Percentage of Principal Payment, Cap												15%
Long-Term Line of Credit								$ 134,000		$ 134,000		$ 161,000
Clyra Medical [Member] \| Notes Payable, Other Payables [Member]
Debt Instrument, Face Amount													$ 100,000
Debt Instrument, Interest Rate, Stated Percentage													8%
Debt Instrument, Convertible, Sale of Stock Amount													$ 5,000,000
Debt Instrument, Convertible, Conversion Percentage													70%
Vernal Bay Capital Group, LLC [Member] \| Conversion of Clyra Medical Stock Into Biolargo Common Stock [Member]
Conversion of Stock, Shares Issued (in shares)			527,983

[1]Aggregate intrinsic value based on closing common stock price of $0.17 at September 30, 2023.

Note 8 - Noncontrolling Inter_4

Note 8 - Noncontrolling Interest - Clyra Medical - Common Shares Outstanding (Details) - Clyra Medical [Member] - $ / shares	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Options outstanding, balance (in shares)		15,833	14,004	14,004
Balance, Exercise Price Range (in shares)			1	1
Weighted average exercise price per share, balance (in dollars per share)		$ 5.53	$ 1	$ 1
Exercised (in shares)	(2,964)	(2,964)
Exercised, Exercise Price Range (in dollars per share)		$ 1
Exercised, Weighted Average Price Per Share (in dollars per share)		$ 1
Options granted (in shares)		1,215	1,403
Granted, Exercise Price (in dollars per share)			$ 1
Weighted average exercise price per share, granted (in dollars per share)		$ 171.99	$ 1
Options outstanding, balance (in shares)	14,084	14,084	15,407	15,833
Balance, Exercise Price Range (in shares)			1
Weighted average exercise price per share, balance (in dollars per share)	$ 20.85	$ 20.85	$ 1	$ 5.53
Minimum [Member]
Balance, Exercise Price Range (in shares)		1
Granted, Exercise Price (in dollars per share)		$ 1
Balance, Exercise Price Range (in shares)	1	1		1
Maximum [Member]
Balance, Exercise Price Range (in shares)		310
Granted, Exercise Price (in dollars per share)		$ 271
Balance, Exercise Price Range (in shares)	310	310		310

Note 8 - Noncontrolling Inter_5

Note 8 - Noncontrolling Interest - Clyra Medical - Valuation Assumptions (Details)	9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Clyra Medical [Member] \| Vendors and Employees [Member]
Risk free interest rate			2%
Expected volatility			40%
Expected life in years (Year)	10 years		10 years
Maximum [Member] \| Clyra Medical [Member] \| Vendors and Employees [Member]
Risk free interest rate	4.15%
Expected volatility	49%
Non Plan [Member]
Risk free interest rate	4.15%
Expected volatility	112%
Expected life in years (Year)	10 years
Non Plan [Member] \| Minimum [Member]
Risk free interest rate	2.32%
Expected volatility	115%
Non Plan [Member] \| Minimum [Member] \| Clyra Medical [Member] \| Vendors and Employees [Member]
Risk free interest rate	3.48%
Expected volatility	40%
Non Plan [Member] \| Maximum [Member]
Risk free interest rate		3.83%
Expected volatility		117%

Note 8 - Noncontrolling Inter_6

Note 8 - Noncontrolling Interest - Clyra Medical - Summary of Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Accounts payable	$ 670	$ 717
Accrued payroll	194	198
Accrued interest	25	25
Accounts payable and accrued expenses, total	889	940
Clyra Medical [Member]
Accounts payable	158	186
Accrued payroll	12	45
Accrued interest	8	7
Accrued dividend	152
Accounts payable and accrued expenses, total	$ 330	$ 238

Note 9 - BioLargo Engineering_2

Note 9 - BioLargo Engineering, Science and Technologies, LLC (Details Textual) - USD ($)	1 Months Ended	9 Months Ended		12 Months Ended		25 Months Ended
	Sep. 30, 2017	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021	Sep. 30, 2019
Share-based Payment Arrangement, Noncash Expense, Total		$ 1,269,000	$ 1,455,000
Seven Employees Working at BioLargo Engineering, Science & Technologies, LLC [Member]
Deferred Compensation Arrangement with Individual, Requisite Service Period (Year)	5 years
Potential Ownership Percentage of Subsidiary Held by Subsidiary Employees Based on Performance	30%
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)				1,242,500
Incentive Issuance Stipulations for Subsidiary Employees, Accounts Receivable Collected by Year One of Operation	90%
Incentive Issuance Stipulations for Subsidiary Employees, Profit Earned in Year One of Operation	10%
Percentage of Profit Interest					13%
Percentage of Profits Interests Vested				18%	11%
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested in Period, Fair Value				$ 135,000	$ 65,000
Seven Employees Working at BioLargo Engineering, Science & Technologies, LLC [Member] \| Share-Based Payment Arrangement, Tranche One [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)					455,000
Seven Employees Working at BioLargo Engineering, Science & Technologies, LLC [Member] \| Share-Based Payment Arrangement, Tranche Two [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)					525,000
Seven Employees Working at BioLargo Engineering, Science & Technologies, LLC [Member] \| Non-Qualified Stock Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)	1,750,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)	5 years
Share-based Payment Arrangement, Noncash Expense, Total						$ 0
BioLargo Engineering, Science & Technologies, LLC [Member]
Subsidiary, Ownership Percentage, Parent	100%

Note 10 - BioLargo Energy Tec_2

Note 10 - BioLargo Energy Technologies, Inc. (Details Textual) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023	Sep. 30, 2017
BioLargo Energy Technologies, Inc (BETI) [Member]
Stock Issued During Period, Shares, New Issues (in shares)	10,000	467,000
Proceeds from Issuance or Sale of Equity	$ 25,000	$ 1,005,000
Stock Conversion, Discount on Volume Weighted average Price	20%	20%
Shares, Outstanding (in shares)	9,467,000	9,467,000
BioLargo Energy Technologies, Inc (BETI) [Member] \| Biolargo [Member]
Proceeds from Issuance or Sale of Equity		$ 100,000
BioLargo Energy Technologies, Inc (BETI) [Member]
Investment Owned, Balance, Shares (in shares)	9,050,000	9,050,000	9,000,000

Note 11 - Business Segment In_3

Note 11 - Business Segment Information (Details Textual)	9 Months Ended
Note 11 - Business Segment Information (Details Textual)	Sep. 30, 2023
Number of Operating Segments	5

Note 11 - Business Segment In_4

Note 11 - Business Segment Information - Segment Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Revenue from Contract with Customer, Including Assessed Tax	$ 2,672,000	$ 1,500,000	$ 7,860,000	$ 3,786,000
Research and development	(694,000)	(271,000)	(1,846,000)	(1,018,000)
Operating loss	(1,537,000)	(943,000)	(3,574,000)	(3,973,000)
Interest income (expense)	(12,000)	(14,000)	(72,000)	(42,000)
Tangible assets	5,753,000		5,753,000		$ 3,958,000
Operating Lease, Right-of-Use Asset	777,000		777,000		867,000
Investment in South Korean joint venture	15,000		15,000		33,000
Total	6,545,000		6,545,000		4,858,000
Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	15,000		15,000		33,000
Corporate, Non-Segment [Member]
Revenue from Contract with Customer, Including Assessed Tax	0	2,000	0	4,000
Research and development	(234,000)	(140,000)	(665,000)	(570,000)
Operating loss	(797,000)	(783,000)	(2,230,000)	(2,925,000)
Interest income (expense)	(3,000)	(6,000)	(43,000)	(18,000)
Tangible assets	579,000		579,000		669,000
Operating Lease, Right-of-Use Asset	72,000		72,000		136,000
Total	666,000		666,000		838,000
Corporate, Non-Segment [Member] \| Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	15,000		15,000		33,000
Operating Segments [Member] \| Odor-No-More [Member]
Revenue from Contract with Customer, Including Assessed Tax	2,513,000	1,199,000	7,374,000	2,499,000
Research and development	(14,000)	0	(14,000)	0
Operating loss	969,000	400,000	2,786,000	418,000
Interest income (expense)	(1,000)	0	(5,000)	0
Tangible assets	3,300,000		3,300,000		2,064,000
Operating Lease, Right-of-Use Asset	0		0		0
Total	3,300,000		3,300,000		2,064,000
Operating Segments [Member] \| Odor-No-More [Member] \| Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0		0
Operating Segments [Member] \| Clyra Medical [Member]
Tangible assets	1,202,000		1,202,000		631,000
Operating Lease, Right-of-Use Asset	0		0		0
Total	1,202,000		1,202,000		631,000
Operating Segments [Member] \| Clyra Medical [Member] \| Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0		0
Operating Segments [Member] \| BLEST [Member]
Tangible assets	480,000		480,000		441,000
Operating Lease, Right-of-Use Asset	705,000		705,000		731,000
Total	1,185,000		1,185,000		1,172,000
Operating Segments [Member] \| BLEST [Member] \| Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0		0
Operating Segments [Member] \| BioLargo Water [Member]
Revenue from Contract with Customer, Including Assessed Tax	22,000	1,000	31,000	1,000
Research and development	(128,000)	(119,000)	(401,000)	(446,000)
Operating loss	(155,000)	(141,000)	(549,000)	(572,000)
Interest income (expense)	0	0	1,000	0
Tangible assets	89,000		89,000		194,000
Operating Lease, Right-of-Use Asset	0		0		0
Total	89,000		89,000		194,000
Operating Segments [Member] \| BioLargo Water [Member] \| Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0		0
Operating Segments [Member] \| BioLargo Energy Technologies, Inc (BETI) [Member]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0	0
Research and development	(537,000)	0	(840,000)	0
Operating loss	(559,000)	0	(943,000)	0
Tangible assets	144,000		144,000
Operating Lease, Right-of-Use Asset	0		0
Total	144,000		144,000
Operating Segments [Member] \| BioLargo Energy Technologies, Inc (BETI) [Member] \| Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0
Operating Segments [Member] \| BioLargo Engineering, Science & Technologies, LLC [Member]
Revenue from Contract with Customer, Including Assessed Tax	843,000	401,000	1,742,000	1,613,000
Research and development	(433,000)	(100,000)	(971,000)	(288,000)
Operating loss	(568,000)	(179,000)	(1,388,000)	(158,000)
Operating Segments [Member] \| Clyra Segment [Member]
Revenue from Contract with Customer, Including Assessed Tax	14,000	17,000	20,000	34,000
Research and development	(68,000)	(31,000)	(262,000)	(73,000)
Operating loss	(427,000)	(240,000)	(1,250,000)	(736,000)
Interest income (expense)	(8,000)	(8,000)	(25,000)	(24,000)
Consolidation, Eliminations [Member]
Revenue from Contract with Customer, Including Assessed Tax	(720,000)	(120,000)	(1,307,000)	(365,000)
Tangible assets	(41,000)		(41,000)		(41,000)
Operating Lease, Right-of-Use Asset	0		0		0
Total	(41,000)		(41,000)		(41,000)
Consolidation, Eliminations [Member] \| Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0		$ 0
Intersegment Eliminations [Member]
Research and development	$ 720,000	$ 119,000	$ 1,307,000	$ 359,000

Note 12 - Commitments and Con_2

Note 12 - Commitments and Contingencies (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating Lease, Expense	$ 88,000	$ 59,000	$ 254,000	$ 228,000
Operating Lease, Weighted Average Remaining Lease Term (Year)	9 years		9 years
Lessee, Operating Lease, Discount Rate	18%		18%
Westminster, California Facility Lease [Member]
Lessee, Operating Lease, Renewal Term (Year)	4 years		4 years
Oak Ridge, Tennessee Facility Lease [Member]
Operating Lease, Weighted Average Remaining Lease Term (Year)		10 years		10 years

Note 13 - Subsequent Events (De

Note 13 - Subsequent Events (Details Textual) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
Note 13 - Subsequent Events (Details Textual) - USD ($)	Nov. 13, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Proceeds from Issuance of Common Stock				$ 1,497,000	$ 3,267,000
Lincoln Park Capital Fund, LLC [Member]
Stock Issued During Period, Shares, New Issues (in shares)		1,190,223	2,440,958	2,833,846	4,353,919
Proceeds from Issuance of Common Stock		$ 203,000	$ 485,000	$ 502,000	$ 903,000
Subsequent Event [Member] \| Lincoln Park Capital Fund, LLC [Member]
Stock Issued During Period, Shares, New Issues (in shares)	873,788
Proceeds from Issuance of Common Stock	$ 142,000