Water Clarifier (8.45 oz)Clear cloudy or hazy aquarium water in just a few hours with TetraAqua WaterClarifier. Safe for all freshwater aquariums, TetraAqua WaterClarifier is phosphate-free. It will not affect bio-filtration, pH, or any other water parameters, and it is safe for fish and plants. Unlike many clarifiers on the market, Tetra's formula is safe for fish even in very soft water (low KH) conditions. One teaspoon treats 10 gallons.