I recently bought two K&H heated water bowls that hold each hold 1 1/2 gallons of water. I recommend them highly. http://www.amazon.com/K-H-Thermal-Assorted-Colors/dp/B000Y8GQ56 They're working wonderfully. What's really GREAT is that they are MUCH easier to maintain than the plastic waterers that I got from TSC. The ones from TSC were/are a pain in the neck to fill. To fill the pet bowls, we just take a bucket of water out and pour the water in, no mess, no fuss. Even in the summer, I'm going to unplug the bowls and continue using them. If I have chicks to raise though, I'll use the TSC waterers because small chicks could/would fall into the K&H bowls and drown for sure.