It depends on how many chickens are in the pen. For my largest group I put one of those 44 watt flat foil bird bath de-icers ($18.16 with free shipping on eBay) on a cinder block (holes up so the heater doesn't overheat) and placed a 3 gallon waterer on top. It's in their run. The whole coop is wrapped in clear plastic so their "outside" is now "inside" sort of. The sun heats up the run now that it's wrapped so that helps, too.What do you guys all use to heat water? I bought a metal water fountain and just got my Farm Innovators heated base, but it states not to use an extension cord, which I will need to use. And also where can I safely place it in the coop? I'm afraid that it could catch fire if straw or something falls on it. Any thoughts? Does anyone use this base? If not I will ship it back and get something else.
Thanks!