Gone are the days of manually adding water to your tank. Aquarium maintenance just got easier! FL!PPER Automatic Top Off (ATO) System keeps your aquarium water levels perfect using Simple Physics... no floats, switches, or electronics which can fail. Stable water levels result in consistent salinity which keeps your tank inhabitants happy and healthy. Freshwater tanks benefit from one less daily maintenance chore. Take a vacation knowing your water levels are under control! Flipper's beautiful high-quality clear acrylic ATO automatically tops off your aquarium with freshwater to your desired water level. Perfect for fresh and saltwater tanks!