Chemi-Pure aquarium filter media removes ammonia and other harmful waste products and toxins from aquarium water, regulates pH and contains no phosphates. Chemi-Pure is a safe, effective filter media for creating crystal clear aquarium water, reduces water changes, makes fish healthier, and allows corals and invertebrates to acclimate more quickly and thrive in their aquarium environment. Chemi-pure has no effect on beneficial biological organisms and can remove copper from medication dosage. Ideal for freshwater or saltwater aquariums, Chemi-Pure is the perfect replacement for any aquarium filter using bags of carbon media. Take your aquarium filtration to the next level with Chemi-pure! Treats up to 20 gallons.