The Floating De-Icer will keep a stock tank completely ice-free all winter. The thermostatic control coupled with thermal feedback protects the unit from overheating, and ensures efficient operation. The stainless steel heating element is positioned above the thermostat for safey even in low-water conditions. The float is completely enclosed in a rugged, plastic housing and will not sink over time. Recommended for 100-300 gallons of water.