I am just feeding them regular chicken food, watermelon and that's about it. they've got a large dam with lots of bugs so I don't have to feed them very often
I don't know the difference between the crumble and pellets, but the stuff im feeding them is just straight seed they seem to be able to eat the small pieces though
If what you're feeding is just grain then it does not have enough niacin for ducklings. What types of feed are available in your area? Here in the US most of us can get something like Purina Flock Started or Nutrena All Flock, can you get something like that? If not, can you get a chick crumble?