Note 2 - Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2018

Notes Tables

Schedule of Cash and Cash Equivalents [Table Text Block]

	DECEMBER 31, 201 7		March 3 1 , 201 8
BioLargo, Inc. and wholly owned subsidiaries	$	461,914	$	574,106
Clyra Medical Technologies, Inc.		528,543		347,836
Total	$	990,457	$	921,942

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

	March 31, 2017			March 31, 2018
Customer A		28	%		39	%
Customer B		17	%		<10	%
Customer C		12	%		<10	%
Customer D		<10	%		18	%
Customer E		<10	%		18	%

	December 31, 2017			March 31, 201 8
Customer A		12	%		23	%
Customer B		19	%		<10	%
Customer C		12	%		<10	%
Customer D		10	%		<10	%
Customer E		10	%		<10	%
Customer F		<10	%		13	%
Customer G		<10	%		11	%

Schedule of Inventory, Current [Table Text Block]

	DECEMBER 31, 2017		MARCH 31, 2018
Raw material	$	34,104	$	48,211
Finished goods		19,869		8,594
Total	$	53,973	$	56,805

Schedule of Segment Reporting Information, by Segment [Table Text Block]

	Odor - No - More			Clyra			BLEST			BioLargo / Other			Total
Revenues	$	224,397		$	—		$	38,632		$	—		$	263,029
Cost of goods/services		(134,464	)		—			(28,728	)		—			(163,192	)
Depreciation and amortization		4,093			—			6,230			—			10,323
Interest expense		—			—			—			832,408			832,408
Expenditures for assets		—			—			18,753			—			18,753
Equipment, net of depreciation		42,299			—			74,996			—			117,295
Net loss		(200,000	)		(198,721	)		(46,387	)		(1,984,460	)		(2,429,568	)
Tangible assets, net		293,997			347,836			140,722			448,542			1,231,097

	Odor - No - More			Clyra			BioLargo / Other			Total
Revenues	$	46,017		$	—		$	—		$	46,017
Cost of goods/services		(22,530	)		—			—			(22,530	)
Depreciation and amortization		7,924			—			—			7,924
Interest expense		—			8,750			944,886			953,636
Expenditures for assets		—			—			—			—
Equipment, net of depreciation		54,121			—			—			54,121
Net loss		(175,000	)		(137,082	)		(2,013,594	)		(2,325,676	)
Tangible assets, net		180,292			268,771			1,015,039			1,464,092