I asked you this a few weeks ago and you didn't answer, so I'll ask again, how big is your pond? A heater is not going to heat all the water in your pond unless it is incredibly tiny. Just think of the logistics of getting a heater to heat hundreds of gallons of water, it simply isn't a matter of sticking a heater in the water like in an aquarium. Usually pond heaters just float on the top and keep a hole in the ice open for gases to escape, but that is not enough warmth to raise the temp of the pond. What state are you located in?