This easy-to-setup and easy-to-maintain Top Fin Undergravel Filter works to help cleanse aquarium water of harmful compounds and odors. Help ensure the safety of the water in your aquatic pet's aquarium with the help of this highly effective filter, which works to remove harmful compounds and the causes of odors for clean aquarium water. This filter is easy to set up and easy to maintain. Features: Filters aquarium water to remove harmful compounds and odors to help keep your fish happy and healthy Easy set up and maintenance Includes cartridge, carbon canisters, spout, airline tubing, air stone, top tube, tube connector, bottom tube, base joint and panels 1 year warranty Includes: 1 Filter Intended For: Aquariums Size: Available in small (for 10 to 20-gallon aquariums) and large (for 10 to 40 gallon aquariums) Instructions: Place assembled air filter into aquarium tank. Replace the air stone when air flow becomes sluggish. Change the cartridge every 2 4 weeks depending on the water condition. Wash the uplift tube assembly when it becomes dirty. Caution: Do not use soap or detergent as they can be toxic to fish. Size: Small.