An easy-to-use, single-cartridge tap water filtration system that removes impurities from tap water, making perfect, deionized aquarium water. Filter resin changes color when it's time to replace cartridge. Used cartridge can be replaced without tools in minutes. Comes fully assembled and attaches to any faucet in seconds. Includes 4 oz. bottles of Electro-Right and pH Adjuster to treat the filtered water, faucet adapter and tubing. For freshwater, saltwater, African cichlid or community aquariums.