The SUNSUN HW-303B external 4 stage canister filter is ideal for tanks up to 100 gallon. It handles up to 370 gallons per hour. The Super HW-303B includes filter pads, hoses and all the parts you need to get started. The three flexible media trays allow you to add other filtration media such as activated carbons, ceramic rings or bio-balls (each sold separately) to achieve excellent mechanical, chemical, and biological filtration. A built in 9 Watt UV sterilizer helps control algae spores/bacteria and promotes clear water. The HW-303B canister filter also has a convenient self-priming pump that eliminates the need for manual siphoning.