Hello,
I've had runner ducks before, and they were bonkers lol
I always left food and water "together" outside during the day, so unlimited food, but never in their house at night, as it will be just a sodden mess as they do wash down their food with every mouthful, making it very wet inside.
I also, made sure that I would put them away every night in their house at dusk, as mine would rather go and sit in the middle of their little pond, rather than go inside for safety.
They are daft, but I prefer them over chicken tbh , are very funny, but very, very messy and more smelly!! lol