The unique Rena Smartfilter takes aquarium power filters to the next level of ease and convenience. This new revolutionary design utilizes a unique four-sided filter cartridge to add four times the 3-stage filtering power of a conventional aquarium power filter. Each filter contains a unique Bio Chem Stars tower for extra added biological filtration, effectively adding the filtration power of a more expensive and complex canister filter to this handy package. Other features include a convenient dosing port for adding medications and aquarium water treatments, a caddy designed for easy access for filter maintenance, a motor rack that removes by itself for cleaning without taking apart the filter, as well as a special four-sided filter cartridge designed to fit all sizes. Includes and requires one cartridge.