Fish ponds and decorative water features: Add 1/2 gallon per 1,000 gallons or 1 pint per 100 gallons for control of string algae and other algae. Fish aquariums: For a 16-gallon tank, add 0.1 ...

Is that true? A: I wouldn't say it stops all algae, but there is some evidence that barley straw has compounds that inhibit the growth of filamentous or "string" algae. As barley decomposes ...