I have a flat backed bucket like the one below and I bought watering cups from Farm & Fleet (the ones with the yellow thing inside that the chickens peck at to refill it). I installed them to either side of the front of the bucket (curved side). I used plumbers tape and some rubber washers to prevent leaking. This worked great all summer long. Over the last week or so I've noticed that the bucket has been emptying it out very quickly, but I just figured it was the birds drinking more. Last night as I was sitting with them, I noticed that one of the cups was filled to the brim and overflowing AND leaking from the spout. We took it out, put new plumber's tape on it and put it back in. I let it sit in the house for an hour or so to see if it was still broken and it seemed to be fixed. Today, the same cup was doing the same thing. The other one is fine. The leak seems to be slower now though. We are buying a new bucket and new cups tonight but I would like to know any tips on installing it to prevent this.