first the device I would be using is the MARSHALLTOWN The Premier Line 742G Bucket Water Heater (i found it on amazon). would it work if I put it in a plastic waterer. I'm thinking it is designed for medal, but you never know. I want it in a plastic waterer because they can hold much more water. I need more water for winter because of my increased waterfowl population (I have more than quadrupled my original number of 3, because I added 13 more birds).