I'm in the process of emptying our pond and sinking it deeper into the ground as it was put in a bit wonky! It has become entirely solid with flag irises and marsh marigolds such that there was no clear water - earth worms were even living in there! I've taken out 2/3 of these plants but left a lump as the frogs adore them and the various critters feed off the decaying leaves.
Disrupting the wildlife is concerning me however, and I'm not sure how much of the silt to remove. There's maybe an inch or thereabouts of silt all over, and it stinks when dredged up, but I understand frogs sometimes hibernate in it and the leeches, flatworms, waterlice and maybe the snails too all use it for various purposes.
Would it be best to remove it all and accept that it will inevitably gradually build up again? Or should I save some to put back in there when I'm finished to disrupt the balance as little as possible? I am saving the clearer water and have plenty of rain water to top it up (the waterbutts even have little pond snails in! It rains snails round here it seems!)