The CF500-UV takes UV canister filters to the highest level. This 525 GPH 4+1 filtration system is ideal for fresh and saltwater aquariums up to 175 gallons. The integrated 9 watt UV Sterilizer helps keep your aquarium healthy and crystal clear. The CF500-UV defies its low price because it comes equipped not only with a UV Sterilizer but all the necessary plumbing for installation and includes four large filtration media compartments allowing you to add the filtration media of your choice. The filtration media trays offer a fully customizable filtration system to suit your specific aquatic needs. The CF500-UV includes four fine filter pads (white) and a single coarse filter sponge (blue) for enhanced Mechanical Filtration. With the addition of AquaTop's Premium Activated Carbon, Ceramic Rings, or Bio-Balls (each sold separately), you'll achieve superior filtration and crystal clear aquarium water. The CF500-UV Canister Filter has a convenient Prime Pump that eliminates the need for manual siphoning! Say goodbye to a mouth full of aquarium water!!!