The Aqueon QuietFlow Canister Filter is a dependable, efficient canister filter designed to function in both freshwater and saltwater aquariums. This canister has been preloaded with all you need in a canister filter, including biological, chemical, and mechanical media in order to effectively remove waste and harmful toxins from water. This filter features a convenient back-hanging water polishing unit to help make maintenance fast and simple. Rather than the traditional messy maintenance of other canister filters, simply replace the carbon cartridge with an Aqueon Replacement Filter Cartridge as needed, saving you the trouble of disassembling the canister housing to replace the contents of the media basket. This saves you maintenance time without sacrificing filter quality. If you prefer a traditional water return method, Aqueon is happy to oblige, and this filter includes the connections and outputs needed. If you're looking for a powerful, simple, and space-efficient canister filter, the Aqueon QuietFlow checks all the boxes. The Aqueon QuietFlow Canister Filter comes in three models, the 200 (fits aquariums up to 55 gallons), 300 (fits aquariums up to 75 gallons), and 400 (fits aquariums up to 155 gallons), all of which use Large sized Aqueon Replacement Filter Cartridges.