We have some blue ones that we picked up on eBay cheap. They worked great until the goat started sleeping in the coop and broke half of the system. The downside of them is that they would get dirty and were hard to clean out without a sponge and its a chore to keep a sponge around out here. We have several buckets and chick waterer at the moment. In the future we will be doing the nipples at several heights as we have chickens and turkeys together. And don't do buckets of water if you have baby birds, all of my chickens are mature and turkeys are taller.
