The duck weed will need to be controlled with sonar or I guess there is a new product called whitecap. I think that duckweed doesn't like the surface turbulence of a surface aerator but I don't think it will get rid of it. The FA can be controlled with cutrine plus easily enough as far as the muck on the bottom I have been aerating 3 yrs now on a 1/4 acre pond that was almost septic when we bought the place, the pond is surrounded by trees and the black muck on the bottom was about 12" deep. the dogs would jump in (yellow Labs) and come out half black and smelling terrible, I have just the other day noticed that they stir up a little gray bottom but don't come out with any stain or smell and it feels as though I have very little muck maybe this years leaf foliage which is outstanding as far as I am concerned. I did do the Bacteria last year so I would like to think the combo of a aerator and the bacteria made a difference. I think time will tell if you are doing everything right it will start showing. I had to treat my pond with Sonar to get rid of the WM and DW. Just to give you a idea I show you couple pictures
The black muck
This is before I treated with Sonar
aerator swell barely making a opening in the surface
month and a half later signs of the WM and DW are thinning
something like 60 days later and to date I haven't had a problem with WM or DW and little FA problems. I will spray a little cutrine plus will a slime develops on the surface
