Marina Slim Power Filter S15 – A slim-profile hang-on-back filter for aquariums up to 15 gallons. This filter clips onto the tank and takes up minimal space thanks to its thin design. It uses replaceable filter cartridges to perform mechanical and chemical filtration (trapping debris and removing odors), and also has a small bio-media chamber for beneficial bacteria. The Marina S15 runs quietly and has an adjustable flow, making it suitable even for fish that prefer gentle water movement. It keeps aquarium water clear and healthy with very easy cartridge changes – perfect for a hassle-free filtration solution.