I guess the heated water idea's work great if you only have a few bird's like in one coop.I Have alway's have several coops some with numerous pens.I basicaly spent 3 Cold winter's breaking Water and having extra's sitting inside.They do have the heated base's but they are quite pricey I think and would probably be best on those Big metal water's I dunno. Some of homemade one's here may work I would be careful though depend's on your coop flooring and bedding etc.The heating pad idea seems good since it is an enclosed product to start with.I dunno Im always weary.I had a brooder fire once and grrrrrr never wanna see anything like that again. Hope you can find a good solution it is a lot of work winter for sure.