The waterer on my tractor is a length of 3" pvc with horizontal nipples on the end. Last winter I bought a shatterproof aluminum submersible aquarium heater that was highly recommended on Amazon (Aqueon Pro 100). Even though it was on a thermocube It still only made it half way through winter before burning out, causing my pipe to freeze and bust. I was looking at TSC for a bucket heater but they are to large to fit inside my 3" pipe. Anyone with a similar setup or that is using a heater that fits my dimensions care to recommend a product? Guess I could wrap heat tape on outside if I have to. Here is a pic of my setup so you can see what I'm using.