Nicole Alderman wrote:He doesn't think that koi would do well in that kind of set-up. Duck poop produces too much ammonia, and the dissolved solids would get too high. The ducks stirring up sediment could irritate the fishes' gills. A quote from him, "I mean, you could do it, but you're going to need massive filters that completely negate any hope of financial gain."
How big of a pond are you looking at having? How many ducks are you planning to have? How many hours/day would the ducks have access to the pond? How many water changes do you want to do? Willows and other emergent pond side plants, like cattails and wapatos, take up a lot of nitrogen. Another quote from him, "If you had at least 50,000 gallons with only, like, 3 ducks, and lots of plants, maybe you could pull it off. I'm just guessing on numbers, though--you'd have to test the water frequently for nitrates and ammonia. Duck poop is not like fish poop.