The Supreme Skilter 400 is a combination Power Filter and Protein Skimmer in one; with chemical; mechanical; and biological filtration. It is basically a protein skimmer and aerating power filter in one compact; easy-to-use unit. It is an ideal primary filter for 30 to 100 gallon saltwater aquariums. The protein skimmer portion of the system will handle aquariums up to 125 gallons; provided additional filtration is present. The Skilter 400 is easy to operate. The unit hangs on the back of the aquarium; just like a standard power filter. It is made of high impact plastic for years of dependable use; even under the adverse conditions of a saltwater environment. The Skilter 400 employs a quiet; dependable power unit and impeller assembly. Although compact; this powerful system pumps up to 400 gallons per hour. The built in venturi driven Protein skimmer; has an adjustable air intake tube for contolling foam production; and a combination collection cup/filter lid; makes waste removal quick and easy. The Skilter 400 provides three stages of filtration as oxygen rich water exits the protein skimmer. As water passes through the Supreme Bio-Matrix cartridge. First; it is mechanically filtered by the dense polyester filter material. It then passes through an activated carbon medium that is specially designed to be an effective chemical filter. Finally; the entire cartridge; surrounded by its unique clam-shell style frame; acts as an efficient biological filter. The snap-together cartridge is easy to replace and allows for either partial or total change of the filter media. This assures uninterrupted bacterial filtration. The Skilter 400 uses two Bio Matrix cartridges. The saltwater that is filtered by the Skilter 400 is virtually saturated with oxygen. This increased amount of oxygen that re-enters the aquarium water helps provide a better environment for fish and invertebrates alike. For more information on aquariums and fish keeping; please read our That Fish Blog.