what time of year is best to clean pond?

When is the best time to clean pond? After all leaves have fallen is it not to cold for the fish?

Doug says the best time of year is right after the leaves fall. The second best time is first thing in the spring before the pond gets going.

If you can't clean in the fall, then do remove all the leaves in the pond. They'll rot over the winter, lowering O2 levels in the process and this might create winterkill conditions for fish.