I have 19 chickens and 15 ducks. I use six inches of coarse sand in my run. The chickens love it, and it drains water well which is a necessity for the ducks. I added a drain system in the run since the ducks make such a mess with the waterers. The waterers sit on a 24x24 box which has piping leading outside the run. This way any water the ducks splash outside the waterers drains outside the run.
That looks awesome. I was considering doing something that loops very similar. What does your daily maintenance look like? Do you just kitt litter scoop the sand? I was going to do linoleum and straw in the actual coop...but they will only be there for nights.
Maintenance for the drains involves hosing off the rocks on a regular basis, as they get clogged up with dirt. I am toying with making metal grates to cover the boxes which will support the waterers. That would eliminate 99% of the maintenance. The maintenance in the run is weekly raking, and adding new sand each spring.
The trough on the waterers is 3" wide and 2" deep, so they work for the ducks nicely. They are larger than the usual chicken waterers. I also have 3 gallon water dishes in two corners, so the ducks can take quick baths. Outside the run I have a kiddie pool that is 12" deep that they do their swimming in. Of course, about 150 feet from the coop is a 2 acre pond that the ducks want nothing to do with!