Powkoo Air Pump Sponge Filter Bio Filter for Aquarium Fish Tank Up to 45 Gallons Made of food-grade materials,absolutely safe and filter operation is no noiseMax Tank Size: 45 Gallons Sponge filters provide both mechanical and biological filtration -- Simple, effective,easy to clean (squeeze in tank water), Working perfect getting your fish tank water super clean and clear. Easy to use: Simply install an airline tubing and an air pump into the unit,The water flow exit tube on the sponge filter is adjustable so you can change direction and height of the water flow Dual sponge design, it quickly established a biofilter, two sponges means more surface area for bacteria and faster cycling Can be installed anywhere and can be easily hidden on the back wall of the aquarium; ideal for shrimp tanks, crayfish, fry, fish or breeder aquariums.