Designed and constructed it yesterday. It was cloudy and rainy/snowy here today so I didn't try it out. I hate having to deal with the electric heated bowls, the worry, added expense, volume, etc. I have been trying to think of a way to heat the water or just keep it from freezing during the day and not spend a fortune. SO I have a prototype and will post results tomorrow. High of 27 for tomorrow so it's a good day to see if it is going to work. Wish me luck!