Drain most of the water from the pond.
Catch fish as the water level drops. Make sure that nets or hands are clean and wet before they come into contact with the fish. This protects their delicate slime coats. Place the fish in a bucket of pond water in a shady location.
Remove debris from the pond's bottom. Leave some of the pond sludge in the pond. This slime contains beneficial bacteria that keep the pond healthy.
Clean out all pond equipment. Remove most, but not all, of the sludge from the pond filters. Do this by washing the filters out in a bucket of pond water. The goal is to remove some of the solid matter, not to make it factory clean.
Check pond equipment for needed repairs or replacement before reinstalling them. For items that will freeze, store them indoors for the winter. Frozen water will expand and crack exposed pond filters.
Remove all of the plants from the pond. Clean them up by removing dead, diseased, broken or pest-ridden foliage and roots.
Repot the plants in fresh soil. Bring them into a protected area or place them back in the pond. Check the plant species' requirements on winterizing for advice.
Refill the pond with dechlorinated water.
Add the fish back into the pond or bring them indoors to overwinter.
Hook up the pond equipment if running it through the winter. If storing it, clean the filter and filter pads with hot water before drying and storing them. Alternatively, hook the filters up to an indoor aquarium or other container of water to keep the beneficial bacteria alive.