Here are two of the waters I made this year for my layers. This is a five gallon bucket using a aquarium heater and nipples. So far we have gotten down to 12 F this year and the nipples haven't frozen. The next water straddles the wall between two coops in the chicken barn. It's made of a 21 gallon tote with three nipples on each side. I have a livestock tank heater with the plastic bucket guard keeping this one ice free. No problems with the nipples freezing one this one either. I really didn't have to train the chickens to use the nipples. These waterers were a switch from double walled metal waterers. I had to buy the tote $9.00, the heater $17, the heater cage $10 and the nipples $1.50 each and essentially got 2 waterers. The bucket waterer cost were the aquarium heater $15 and three nipples @ $1.50 each. So far these are working much better than the commercial "heated tin" waterer heater I used on a metal double walled waterer last year. I'm still using it, but in a bigger building that doesn't get as cold as the coops. I've still had to break ice on it in the mornings though.