Aquascape Fermented Natural Barley Straw Liquid Extract 1 Gallon Aquascape Barley Straw Extract for Pond and Stream Features, 1-Gallon MFG Part # 96012 Easy-to-use pump top; 1-gallon bottle treats 80,000 gallons of water; single dose (1 pump) treats 600 gallons 100% fish & plant Safe. Start applications in Spring before Algae is established for best results!