The Ocean Free Stream 3 filter uses "Hydro-Pure" technology to ensure your tank has stable water quality while being environmentally friendly. By filtering through a 3-step process, the Hydra will turn your ammonia, nitrate, nitrite and phosphate into biologically clean water. Suitable for tanks under 2,500 litres. Ultra high efficiency Designed for higher water volume capacity Achieve and maintain optimal water quality and enhance your existing water/ filter system with Hydra Technology. Mu