Recently bought some Mazuri waterfowl food for my Pekins. They don't appear to eat very much, if any. Will they eventually eat it? Should I just only put it and not the previous food? I had been mixing it ...........that way I wouldn't upset any tummies but they still eat the "chick starter" and leave all the little pebbles of Mazuri in the feeder. I really would like for them to eat this ANY ADVICE?