I just use an extra large, high dog water bowl for water and change it once a day (they have clean water in their pools during the day too). I use a grandpa’s feeder for duck pellets. It is a couple feet away from the water and they do not get the feed wet. They do spill some but since I am deep litter with pine shavings it is not a problem. I would think gravel or stones would get food on it and get gross. In deep drying shavings, old food decays without a lot smell.