My ducks were using the duck pond. To avoid this, I placed the pond further away from the chicken coop. Another option is to fence off a separate area for the ducks.
As for feed, ducklings need a special starter feed (Purina/Manna Pro) until 16-20 weeks old. After that, gradually mix it with...
I'm Madeline, but you can just call me Mad. I have 2 goats (Lili, Gipsy) and 3 pigs (Mo, Cho, Pinky). I adore them, they're like children to me, especially the youngest goat, Gipsy.