I can't stand the thought of my chickies pecking at ice, so last year I bought a heated dog water bowl (as others have also said they have done), and it works great. I put it on cinder blocks, sort of like tiered levels to help keep the dirt out when they scratch around the coop. I still change it every day though. No icy water no matter how cold it gets, and it was down around 9 here the other night. Works great!!