The Marineland Penguin 100 Power Filter features complete 3-stage aquarium filtration to keep your aquarium clear; clean; and healthy. The patented Marineland bio-wheel system provides oxygenated surface area for nitrifying bacteria; which keeps your aquarium totally free of harmful ammonia and nitrites. High flow rates maintain optimum water circulation and ensure proper bio-wheel rotation. The adjustable mid-level intake strainer allows you to take aquarium water from mid-tank for complete circulation. The Penguin100 cover design and sealed motor reduces water noise while maintaining optimum oxygenation. The Penguin model 100 uses the handy Rite-Size A filtration media cartridges so choosing the correct replacement media is simple. Penguin filter cartridges take care of all mechanical and chemical filtration in your aquarium and are extremely easy to replace. For complete; easy aquarium filtration for your aquarium; nothing works like a Penguin filter. The Penguin 100 is rated for aquariums up to 20 gallons; and has a maximum flow rate of 100 gph.