I just started doing this and I noticed in just a few days the smell of the duck pen went from stinky to barely any smell. I had to normally clean it out everyday else the poop smell was to much. I am fermenting their normal feed and so it should remain balanced for them. I got the idea here for the fermented feed. I am curious as to any others experiences who have tried this for ducks. Seems like it should be good for them, and its not to much work although I am having to try and figure how much to give them instead of just filling a pan with pellets then taking it away at night. I notice they like it best if its not been out of the ACV/water for more then a few hours. Anyone else doing this?