There is another waterer that can be used. It's real use is for feeding but it works well as a waterer as well. It's a metal dish a few inches deep. The top is slightly convexed (curved) and there are 2" holes all aroung it. The top is threaded and a mason jar screws into it. The dish is just a little larger in diameter than the jar so the birds can't deficate into the holes. These are usually found in feed and grain stores and are used as chick feeders.