Awesome!
And I see you already have your new ones! Sounds like a nice mix you've got. Do you plan to harvest the Cornish x?
Have you raised ducks before? Your white one might be a Pekin and the others could be Rouens or possibly Khaki Campbells. Ducklings can make quite a mess in the brooder with your chicks. How old are they? I found a good tip for a little diy water bin for the ducks so they can wet their nares but won't spill it everywhere, in this thread:
Raising and Caring for Ducklings
And here are some more links to help with your integration:
See But Don’t Touch
Integrating at 4 weeks old