I'm not sure how to access the archives but I spent a lot of time sucking muck out of my pond with a trash pump. There are a couple of threads about doing it. I built a couple of devices to suck it up they all worked. One allows me to stand on the shore and pull it across the bottom of the pond and then pull it back and do it again. Works really good when the muck has been sitting undisturbed for a while after a couple of passes you get down to firmer muck. I use forty feet of intake hose that allows me to keep moving further across the pond without getting into the water and extending the intake pipe. If you can access the archives there is a picture of what I called a hydro dozer. It's what I would pull across the pond