Pond Failing.

Hi. Im moving it around so that it has a better chance to clear the water. Thats the idea anyway. Over the past few days Ive been scooping up the sludge with a net, as suggested. The water is clearing slowly. Ive also added a smaller in pond filter, though the Hozelock is meant to be more than sufficient. Had it not been for the two trees very close, I think it would have been fine. The really odd thing is that while scooping the bottom, I actually came across some baby fish. In the first year I recall there was loads. The bad water and frequent heron visits means there are not many fish in the pond. Ive bought a net and am to figure out how to pull it across a rectangular pond. I was thinking of hooks or screws, screwed to the sides under the top . Anyone done this? Thank you all for your assistance.