I just moved. We have an 1/2 acre sized "pond" having said that I have tried many ways to get it looking someone clean. there is a lot of debris in it I don't want to kill the fish in it. There are a bunch of lilies growing etc. I have a hobby farm going and raise turkeys and chickens and pigs, heifers etc. I was told ducks will naturally clean a pond. But I am not sure about this. And I don't know how old they have to be before they will be safe on their own.