Tetra WaterClarifier 3.38 Ounces, Clears Cloudy aquarium Water Tetra WaterClarifier clears cloudy aquarium water caused by overfeeding, gravel dust and other minute suspended particles. This phosphate-free liquid solution is safe to use in all freshwater aquariums. This effective formula works by causing small, suspended particles to quickly clump together. These larger particles are then removed during normal power filter operation. This formula is based on clarifiers used to treat drinking water. It's safe to use with fish and plants and will not affect water pH levels in your aquarium.Unlike many clarication products on the market, Tetra WaterClarifer is safe for fish even in very soft water (low KH) conditions. However, in extremely low KH conditions, below 1KH, half dosage is recommended. If in doubt about your water's hardness, perform a 20% water change before treatment. Be sure to use Tetra AquaSafe water conditioner for each partial water change and Tetra EasyStrips Test Strips to measure your water's hardness. Since 1951, Tetra has developed the world's most comprehensive body of fish food knowledge, and fishkeeping enthusiasts have looked to the brand for products and solutions that add ease and beauty to their home. Whether you're an experienced hobbyist or just starting out, Tetra has everything you need ? from a large variety of quality fish food and innovative equipment to test kits and decor.