K and H Thermo-Pond is a unique patented pond heater that keeps a hole through the ice in backyard ponds for just pennies a day. For ponds up to 1000 gallons! The world's most energy efficient pond heater!The world's most successful and efficient low-wattage pond de-icer.Uses only 100 WattsMaintains a hole in backyard pond ice for just pennies a day.Thermo-Pond can save up to .00 a month in electricity versus those high wattage stock tank style de-icers! Just think, Thermo-Pond pays for itself in as little as 2 months.Additional features:Floats on top of the water.Thermostatically controlled never to get hot.Completely safe when used with a pond liner or plastic pond.Fish friendly - assists the escape of toxic gases all winter long to help maintain a toxic-free environment for fish living under the ice.Tested in northern Wisconsin at temperatures of 30° below zero Fahrenheit.MET listed for safetyThermo Pond floats on top of the water and is thermostatically controlled to never get hot. Unlike some other heaters, Thermo Pond will never burn a pond liner or plastic pond. It naturally allows the pond to ice over while maintaining a hole through the ice.Allowing that gas exchange can help keep a healthier environment during the winter months Thermo Pond should be used in ponds that are deep enough to allow plenty of livable water under the iced portion of the pond.