I got 3 Indian Runner ducklings a few weeks ago and I feel I must be doing something wrong with the water. The ducklings free-range with the chickens and have several waterers around the yard and all end up with mud in the bottom each day. It doesn't seem to matter if the water is near the food or not, or in the grass or not-so-grassy areas. Is this normal? Will it help to raise the waterers? Is there a type that stays clean easier then others? Thanks for help!