Power Filters 15 Gallon Aquarium Fish Cleaner Tank Hang-on HOB Waterfall Good for up to 15 gallon fish tanks Provides superior mechanical and chemical filtration. The cartridge mechanically filters water through a pad of double thick poly-fiber. Debris and waste particles are trapped, and water is chemically filtered through superior, faster-acting activated carbon. Be able to restart without adding water. This is an important feature to protect your filter and your fish from power failure. Flow rate is adjustable. Special cascade flow design to improve oxygen dissolving