Marineland Penguin PRO Power Filter delivers easy, three-stage mechanical, chemical and biological aquarium filtration. This ultra-quiet filter has a decoupled motor to reduce noise so you can relax and enjoy your aquarium. This power filter contains BIO-Wheel technology to provide wet/dry biological filtration for nitrifying bacteria growth and eliminating toxic ammonia and nitrate fast. Uses Marineland Rite-Size B Filter Cartridge. Filters your 20-gallon aquarium six times per hour with flow control up to 125 GPH. Available in six sizes: 100 (for up to 10 gallons), 125 (for up to 20 gallons), 175 (for up to 30 gallons), 275 (for up to 50 gallons), 375 (for up to 75 gallons), 450 (for up to 90 gallons).