That should be helpful! Whenever I look for what goes for a specie of animal, I always look at their wild diet and then try to adapt what I feed to that as much as possible....here are a few links that describe a little about the diets of some types of wild ducks....sadly enough I Googled for a very long time to just get these few...you are right, the info out there is mighty slim. My thinking is this...if the wild ducks can eat it, so can mine, no matter the breed.
http://www.outdoorlife.com/articles/hunting/2007/09/duck-diets
In the above article it describes some of the many seed grains and grass seeds the various breeds feed on for a large part of their diets.
http://en.wikipedia.org/wiki/Mallard#Feeding
After reading a fair ton on ducks just now I'm wishing I had a body of water for the ones I have coming, even if it's just a slough filled with seepage, because a lot of what they are going to need for breeding and reproducing is located in the water and around water. I'm doubting I could ever replicate the diet a wild duck is able to find but I'll likely try a few things to attract the things they like to eat. We'll see how it all goes....if I can't provide them a quality life, I'll likely get out of ducks.
Metzer farms has a blog on managing waterfowl that Holderread contributes to. It's about as helpful as anything else I've found.
Our ducks have done okay with little kiddie pools. You can fill them every day without wasting a lot of water, or less frequently. But I want to upgrade to some more sturdy water troughs that have drains at the bottom so the flimsy kiddy pools don't have to be flipped.
They like to lay eggs in the water ... they'll sleep in the kiddie pool if you let them. They definitely like to mate in there. And poo. But they don't really need it 24/7.
They live for mud!