Hi, I've been finding my waterer frozen every morning, even when it's inside the coop, and my coop isn't big enough for a bigger waterer. I'm planning on insulating the coop and putting a vinyl shower curtain around the run, but I don't know how much that will help. It's one of those metal bucket-on-it's-side-with-a-rim waterers, but it's 4"x4", and aprox. 2" deep If you have any suggestions for heating it that would be great.