I don't remember where I read this tip, but someone suggested using an old crockpot for a chicken waterer, as it keeps the water warm and unfrozen. After several nights of temps in the low teens and frozen chicken water, I remembered I had an a crock pot in my soap room that I never used because it doesn't have a removable crock and got it out. I filled it with hot water, set it on low and put it in the coop. It works great! It not only keeps the water from freezing, but keeps it warm as well. I notice my chickens don't drink much in the winter and I think it is because the water is so cold. They gobbled this warm water up! It is much easier for me to fill as well. I put it up on a metal tin I was going to make a heater out of, but the crock pot works so well that I don't know that I will bother doing that. It is great. No more cleaning out frozen chicken waterers and filling and toting them back and forth from the house. The crock put wipes up quickly and easily and is easy for me to fill and carry. Just thought I'd pass this along.