The world famous Whisper power filter updated for the 21st century. The Whisper PF10 aquarium power filter offers a host of modern conveniences and advanced filtration capabilities to keep your aquarium clean, clear and healthy. Energy-efficient designs feature low-wattage motors and adjustable flow control. Bio-Foam cultivates and maintains a bacterial bed for biological filtration, while easy to replace Bio-bag cartridges take care of chemical and mechanical filtration. Bio-Bags included.. TimeStrip color tabs included with each filter cartridge tell you when it's time to replace them. Whisper PF10 is designed to filter aquariums up to 10 gallons with a flow rate of 90 gph. Requires 1 medium size Whisper Filter Cartridge .