I currently have a galvanized gravity feeder that sits on a heated base in my coop. If it's not perfectly level, even the slightest bit, it seems that all the water slowly seeps out. I feel I'm wasting at least half. They also keep getting bedding into it and then won't drink it. I'm considering nipples on a bucket but I'm concerned about how well they will work in the cold. Will an aquarium heater in a bucket be sufficient? It gets well below zero here with the wind chill on winter nights. Coldest I've seen without the wind chill was -24.