I shut my pond down for the winter yesterday. I have to do this while it’s still warm enough to step into the water. I pull out all the plants that won’t survive the winter, because if they die in the water they will foul it. Then I shut off the waterfall pump and clean the foam filter out. Then I put a net over the water to catch leaves. The water always goes sour over the winter anyway, but this way it’s much easier to clean up.

I like your descriptive language – ‘foul it’, ‘go sour’ – so many ways to elegantly say, ‘make the pond into brown disgusting goo’.
You’re a poet, man.