F.P.Lover - I think this should work to pump out bottom sludge. However it could be messy and a lot of work. A man has a business near me that uses airlift technology to remove sludge out of small ponds. He used that technology on National Geographic TV to suck sucken treasure from the ocean bottom. Anything that mechanically removes the sludge will work. The ease of the job and efficiency of the operation are two of the critical points.
To me I think an easier and more efficient method of removing bottom sludge would be draining the pond, drying the basin, and using equipment to remove the sludge. While the pond is empty the basin could be remodeled, deepened and maybe reshaped to produce a better water resource. I did that with my main pond when it was 32 yrs old. I have never regretted that operation; now the pond is better than it ever was. I learned from and improved on the first mistakes.
