This filter quietly delivers crystal clear water, and pushes water at 100 Gallons per Hour (GPH) for tanks up to 20 Gallons in size. It’s great for Freshwater and Saltwater aquariums. Accommodating: The adjustable flow knob allows for increased or decreased water flow at will, which is extremely helpful during feeding times, or use it as needed. The hang-on design is constructed for safe mounting. The lift tube is adjustable. Extremely Beneficial: This Cascade filter utilizes disposable, double-sided media cartridges that contain Activated Carbon and Poly Fiber Floss. The included cartridge traps floating particulate matter, removes harmful chemicals and toxins, clears up discolorations, and reduces foul odors from your aquarium’s water. Shop Penn-Plax for All Your Pet’s Needs: Penn-Plax is a manufacturer and distributor of top quality pet supplies, who specialize in creating excellent pet products for animals, both great and small.