The SunSun HW-603 multi stage canister filter is ideal for tanks up to 20 gallon. It handles up to 106 gallons per hour. The SunSun HW-603 includes filter pads, hoses and all the parts you need to get started. There is space above and below filter pads which you can add filtration media such as SunSun's activated carbons, ceramic rings or bio balls each sold separately to achieve excellent mechanical, chemical and biological filtration. To siphon water into the filter, simply fill the filter with water and turn the power on. The SunSun HW-603 can also be used as pre filter for other SunSun canister filters.