I'm new to raising chickens and when I got my chickens the weather was warm and water freezing didn't even enter my mind. Kind of dumb on my part since I live in northern Indiana and we get below freezing temps all winter long. But I've come up with what I think is a good idea and it has been working great with the exception of our -17 degree night. I have a 3 gallon metal waterer that I bought at Rural King. It's the kind that the top slides completly over the bottom or inside. What I did was take the outside and wrapped it with heat tape 12 foot long. It seems long but I wrapped it about an inch apart with the cord coming out at the top. Duck taped it into place all the way around to keep the tape secure to the surface. Then I wrapped it with 3/4" foam that I got from work. I work in a furniture factory and we have lots of scrap foam. Then I sewed up a sleeve with vinyl to fit over the entire thing leaving a slit at the top for the handle and cord to come out. Plug it in and keep the water level up and the water rarely freezes. We have had some really cold weather this year and it has gotton a slight crust of ice on the surface of the water a few times but otherwise it has worked great. I wanted to share that idea with you all because I have gotton so many good ideas from all of you.. Thank you! And maybe this will work for someone else too.