The Pond Digger Brand Liquid Barley Straw Extract is made from all-natural organic barley straw, professional-strength and highly concentrated. This liquid extract undergoes a special stabilization process to ensure a fresh and potent product that rapidly transforms your pond into pristine condition and leaves no residual organics. More effective and faster-acting than barley pellets or bales, this product is completely organic and fish-safe. Use 1 ounce per 1000 gallons, product has 18 month shelf life.