I am not have a very successful hatch rate with ducks in my incubator. I candle them and they all seem to be fertile and developing, but very few make it out of the shell.
Thats funny because I have always had excellent hatch rates from waterfowl in general, ducks and geese. They've been popping out like popcorn all spring. I mist all my duck and goose eggs once a day and turn them once by hand in addition to them being in a turner.