The Marina i110 is a compact yet powerful internal filter for use with any goldfish or tropical tank up to 100 liters (25 US gallons). Complete 3-stage filtration (mechanical, chemical, biological) is provided thanks to its uniquely designed Power Cartridge (included). The outside of the power cartridge features polyester foam to trap fine particles; while the inside chambers contain carbon to remove pollutants and odors; and zeolite to eliminate toxic ammonia for a cleaner, healthier aquarium environment and crystal clear water. The Bio-Screen, with its large surface area, is designed to promote the growth of friendly bacteria.