Remove sediment whenever necessary, which should be whenever you clean out your pond, from once a year to once every few years. According to the Pond Shoppe website, you should take a visual assessment of the pond to determine when it needs cleaning. Clean when algae gathers or the pond becomes murky. Choose a date in early spring before the temperatures get warm so that you don't interfere with the natural summer ecosystem of the pond.
Remove the animal life from the pond before cleaning it out. Catch all fish, frogs and other pond creatures with a fish net and place them in water-filled containers while you work on the pond. Place a screen over each container to prevent frogs and other mobile critters from jumping out.
Drain the water from the pond with a sump pump. Connect piping to the sump pump to drain the water outside the pond and place the sump pump in the pond. Turn the sump pump on and let it drain all the water.
Get down into the emptied pond and take out any large rocks, branches and other debris. If the plants around your pond need pruning and the pond water has been in the way of this task, prune the plants before refilling the pond.
Clean all of the items left inside the pond. Turn the sump pump on and spray everything down with the highest level on your garden hose. Continue to spray the items until the water that comes out of the sump pump runs clear. The majority of the sediment build-up in the garden pond is removed during this stage.
Refill the pond with the hose. When the pond is halfway full, place the containers that hold the fish down into the pond, water and all. This allows the fish to acclimate to the change in water temperature.