You can raise ducks and chicks together in adulthood but do NOT brood them together.
Chicken need dry environment, ducks will make everything around wet and messy, even if they can just wet their beaks in the shallow container.
Would you like to live in the bathroom when there is somebody taking a shower around the clock no shower curtain, you'll be wet around the clock?
That's what you put your chicks through brooding them with ducks.
Have mercy if you really love animals and do NOT brood any waterfowl with other fowl.
Pascopol, I've raised them both just never at the same time. My chicks have always made just as much wet mess so unless I see otherwise, I think they'll do o.k. I raise them in the bathtub for the first couple wks anyway. Nice and toasty.
My ducks and chickens get along very well. Adult ducks can eat chicken food. Female ducks can be fantastic layers, my buff girl outlaid some of the hens last year. So the extra calcium in chicken layer feed is great for them.
I've heard conflicting things about medicated chick feed being dangerous, probably depends on what med is used. Anyway you should have unmedicated chick feed or duckling feed to start out with. Ducklings and chicks can't be raised together anyway, ducklings are way too messy and they get big super fast.
Ducks are unbelievably messy with their water, you can forget about having waterers in the coop. Which for me meant building a secure outdoor space for them attached to the coop, otherwise they'd be without water until I get up to let them out.
Another thing to keep in mind, drakes can be very aggressive with hens, to the point of killing them. So it's a really good idea to have a backup plan and a seperate place to put them if they don't get along.