This thread needs to keep going!! This winter, my PVC system froze, as it got colder than I expected, and one of the nipples was pushed out of its hole in the PVC. Now I have the hole plugged and need to prepare for next winter.
There are plenty of good examples of bucket heaters here, which is the easy part and supported well by retailers. In order to keep the PVC from freezing though, we need to circulate the water. I wonder if
submersible pumps could help. In line pumps are more expensive so I did not look at those. I imagine water pumped from the bucket to the end of the PVC and pushes the water through the PVC back to the bucket. If the heater and pump are all hooked to a
thermocube so they aren't running all the time.
I also wonder about PEX tubing, as this is more cold resistant. It does have a bend in it though and could may make it hard to place the nipples straight down.
Should these things fail, the post about heat cable in the water system used for their rabbits may work, though I would be curious about the materials of the cable as to not introduce nasty chemicals into the water.
*Edit: I found this
heat cable with PVC wrapped wires. FOOD SAFE!! It has it's own thermostat. May be the way to go for next winter.