Note 9 - Intangible Assets and Goodwill - Summary of Intangible Assets (Details) - USD ($)	Mar. 31, 2019	Mar. 31, 2018
Intangible Assets, Gross Carrying Amount	$ 3,381,449	$ 3,101,070
Intangible Assets, Accumulated Amortization	(2,156,192)	(1,788,598)
Intangible Assets, Net Book Value	1,225,257	1,312,472
Trade Names [Member]
Intangible Assets, Gross Carrying Amount	580,000	442,000
Intangible Assets, Accumulated Amortization	(319,913)	(229,480)
Intangible Assets, Net Book Value	260,087	212,520
Customer Relationships [Member]
Intangible Assets, Gross Carrying Amount	751,000	751,000
Intangible Assets, Accumulated Amortization	(194,270)	(119,170)
Intangible Assets, Net Book Value	556,730	631,830
Noncompete Agreements [Member]
Intangible Assets, Gross Carrying Amount	69,700	69,700
Intangible Assets, Accumulated Amortization	(37,638)	(23,698)
Intangible Assets, Net Book Value	32,062	46,002
Certification Marks [Member]
Intangible Assets, Gross Carrying Amount	47,000	47,000
Intangible Assets, Accumulated Amortization	(25,380)	(15,980)
Intangible Assets, Net Book Value	21,620	31,020
Licensing Agreements [Member]
Intangible Assets, Gross Carrying Amount	250,000	250,000
Intangible Assets, Accumulated Amortization	(59,967)	(18,058)
Intangible Assets, Net Book Value	190,033	231,942
Patents [Member]
Intangible Assets, Gross Carrying Amount	1,090,000	1,090,000
Intangible Assets, Accumulated Amortization	(1,090,000)	(1,090,000)
Intangible Assets, Net Book Value
Computer Software, Intangible Asset [Member]
Intangible Assets, Gross Carrying Amount	571,507	429,128
Intangible Assets, Accumulated Amortization	(428,309)	(291,405)
Intangible Assets, Net Book Value	143,198	137,723
Other Intangible Assets [Member]
Intangible Assets, Gross Carrying Amount	22,242	22,242
Intangible Assets, Accumulated Amortization	(715)	(808)
Intangible Assets, Net Book Value	$ 21,527	$ 21,435