The Thermo-Pond™ unique patented design maintains a hole in backyard pond ice for just pennies a day. Unlike stock tank heaters that use up to 1600 watts, the Thermo-Pond™ is so efficient that it uses only 100 watts, saving you as much as $30 to $50 a month in electricity. Thermo-Pond™ floats on top of the water and is completely safe when used with a pond liner or plastic pond. The design of the Thermo-Pond™ assists the escape of toxic gases all winter long to help maintain a toxic-free environment for fish living under the ice. Thermo-Pond™ has been tested to 30º below zero Fahrenheit. One year limited warranty. Patented.

See below for calculating how many heaters you need.