For those who keep ducks and chickens together...what do you feed them?

[JNC]

I heard this too so I'm trying to figure out how to manage this. I'd like to just have one feed for both since having two and making sure that only the ducks are eating one and the chickens the other sounds impossible. My chickens are a year old and they are eating a layer feed right now. My ducklings are only a month old. I plan on housing them both together in about 5 weeks so the ducklings won't be old enough to lay yet. How have people troubleshooted this before?

I have the All flock pellets country road from rural king and then have a separate bowl with oyster shells that the drakes don’t seem to pick at