Hello, and welcome! I don't have ducks, only chickens. I think that if I had both, I would keep them separate from each other. Will a male duck try to breed chicken hen's, since you have no rooster?
i use the rubber pans and use 2 washed out milk gallons to fill them. if the water freezes in the rubber pan just flip it over step down on it and the ice dislodges. i fill it once when they come out in the morning, then i fill again a few hours before night when i check for eggs again. too easy honestly as im already gonna be out there and the milk jugs are easy to lug around.
fyi i have 13 chickens and no ducks. i do know they make the rubber pans in big sizes as well but idk what ducks need as far as water goes.