Aqueon QuietFlow Canister Filters are designed for both freshwater and saltwater aquariums. The canister is preloaded with biological, chemical and mechanical media to efficiently remove waste and harmful toxins from water. Additional replacement filtration media is also available. Included is a unique hang on the back water polishing unit that makes maintenance quick and easy. Instead of disassembling the canister housing to replace the contents of the media basket, simply replace the carbon cartridge. This cuts down maintenance time and means less frequent changes to the media baskets. If a traditional water return method is preferred, i.e. spray bar or water director, the connections and outputs are included.