Ok, after doing some research, and lugging tons of buckets of water down to the coop, I think I want a rain barrel system with nipples or watering cups. Living in Iowa, we have quite cold weather in the winter and I am wondering if any one has made a system that works when in is below freezing with nipples or cups. My other question is, should I used nipples or cups. My chickens were not raised with nipples and I read a thread that it is difficult to train them once they are older, is this true? Also I would love to see others rain barrel/nipple watering system to get some ideas. Thanks!