Help eliminate spring algae by adding  barley straw during the winter. Discourages any unwanted algae growth. Safe and Organic. 8oz. Barley Straw Bundle Treats 800 to 1200 gallons. Barley bundles are inexpensive and healthier for your fish and plants than chemicals. Barley straw has been used for centuries in Europe to maintain fish and garden pond water quality. They have been proven environmentally safe and are inexpensive.