Oh yea I meant to give you a solution to the ducks eating the fish food. Try feeding the ducks chicken scratch on the shore line before feeding the fish. After a while the ducks will come running to you and will leave the fish food alone.
If the ducks are on the shore eating instead of in the water they are not dropping waste in the water, thus not screwing up the water chemistry. Just some advice from someone that has been there.
Keep the duck numbers low, so that you will not run into the aforementioned water problems. By the way Geese leave a lot more waste behind than ducks do, so be aware of that.
