FritzPond Barley Extract is the all-natural way to keep pond water clear. FritzPond Barley Extract provides the same benefits of barley straw but without the mess. Enzymes derived from the natural barley fermentation process help promote a healthy and naturally clear pond. Use every other week to naturally maintain clear water. FritzPond Barley Extract is compatible with FritzZyme® biological products and all other FritzPond conditioners and clarifiers. Naturally clarifies pond water Safe for all plants and aquatic life Concentrated, easy-to-use formula Directions & Dosage Initial dose: Use 1 cup (8 oz) per 500 US gallons (1,893 L). Maintenance dosing: Add 1 oz (1/8 cup) per per 500 gallons. Add maintenance dose every other week. Discontinue use when water temperature falls below 45°F.