I agree completely with iwiw60! Best move I ever made was going with horizontal nipple waterers. They don't leak, water stays clean, and they are not that expensive. I bought a package of 10 and I've got 5 of them screwed into the lower side of a 5 gallon bucket from Lowes with 5 in reserve. We drilled a small "tap hole" in the lid of the bucket. No issues whatsoever.
I started out with the vertical nipples in a smaller bucket but those do leak when the chickens drink. I put it away, planning to use it for chicks, but after a near disaster when we left town for over a week and the 5 gal was close to dry (each daughter thought the other was filling it) I put the little one back in the coop. That way if the main waterer ever goes dry again (and after last time I doubt that will ever happen again) they have an alternate source. My husband is very active in a fraternity and we travel a lot for that, so the peace of mind when we leave town is well worth it. Most of our trips are for 2 or 3 days, so I can fill it the morning we leave and they do fine. The girls learned their lesson and check it regularly now, and haven't had to do much but top it off with a little cold, fresh water by the 3rd day.
