Note 8 - Noncontrolling Interest - Clyra Medical (Tables)

3 Months Ended

Mar. 31, 2023

Notes Tables

Schedule of Other Ownership Interests [Table Text Block]

						Weighted
		Clyra				average
	Options		Exercise			price per
	Outstanding		price per share			share
Balance, December 31, 2022		15,833	$1.00	-	310	$	5.53
Granted		426	1.00	-	271		148.27
Balance, March 31, 2023		16,259	$1.00	-	310	$	9.27
Balance, December 31, 2021		14,004	$		1.00	$	1.00
Granted		648			1.00		1.00
Balance, March 31, 2022		14,652	$		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		3.48	%		3.48	%	2.32	–	3.83%	2.32	–	3.83%
Expected volatility		114	%		114	%	114	–	117%	114	–	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		Intercompany amounts			Totals
Accounts payable	$	169	$	794	$	37	$	121	$	(82	)	$	1,039
Accrued payroll		36		49		75		—		—			160
Accrued interest		25		—		—		—		—			25
Total												$	1,224

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]

	March 31, 2023			December 31, 2022
Risk free interest rate	3.88	–	4.27%		2.32	%
Expected volatility		40%			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	$	235	$	186
Accrued payroll		6		45
Accrued interest		8		7
Accrued dividend		29		---
Total	$	278	$	238