Hello all. I have a existing rentention pond that is in pretty bad shape, had and still does have some duckweed on surface which I manually removed and used herbicide to get it under control. The pond has a bottom aerator to help. What I need to figure out is the best way to go about “muck” which seems to be pretty thick at my end of the pond, and I assume the whole thing. Also what is the next step at keeping the duckweed in check?