Pond Cleaning

Cleaning your garden pond may seem like a daunting task, but with the right equipment and the patience to wait for the pond to drain and refill, it can be a simple job. Depending on the number, size and/or type of fish there happen to be living in the pond, the cleaning may need to be done twice annually, though normally a single autumn cleaning is sufficient. If the pond contains primarily koi, the pond may require a cleaning every few months - but that's another subject. This topic is annual cleaning, which is a bit more involved than a simple water change but which nonetheless is likely to take no longer than a day to do...normally just an afternoon for all but the largest ponds.


  • A Pump sufficient to empty the pond relatively quickly - along with enough Tubing. Often a pump used for a waterfall or biological filter will do, though some of the plumbing may need to be temporarily re-routed.
  • A Net with which to catch fish and/or scavengers.
  • A watertight container large enough to hold the fish and/or scavengers from the pond. In many cases a Whiskey Barrel or trash can with a fresh bag to line it, will work well.
  • Netting to place over the temporary container so that the fish can't jump out.
  • A wet-dry vacuum for removing the debris from the pond bottom.
  • A nylon bristle scrub brush for removing any stubborn algae buildup on the liner and/or rocks.
  • A pressure washer (optional) also for removing stubborn algae buildup.
  • A bucket
  • A measuring spoon
  • An Air Pump, Air Stone, Tubing, and Clamps or a Submersible Pump for temporary aeration.
  • A Thermometer.
  • A nylon broom and plastic dustpan
  • A Dechlorinator (if using municipal water supply). Well-water users may still want to use Pon Salt to minimize stress on fish.


    1. Set up the holding tank for the fish and/or scavengers in a well-shaded area. Fill the holding tank using water from the pond. Provide aeration with the air pump or submersible pump.
    2. Pump the water out of the pond until the water reaches a depth of 6" or so...this will facilitate the removal of plants, fish, and scavengers. Be careful not to flood your neighbor's yard.
    3. After removing your aquatic plants and placing them in a shady area, cover them with wet newspaper or towels.
    4. Transfer the fish and scavengers to your holding tank. Add the proper dosage of Pon Salt or Stess Coat to ease stress. Cover the tank with netting.
    5. Pump the remaining water out of your pond.
    6. Clean your filters. (See Filter Maintenance information here).
    7. Use a nylon scrub brush or power washer to remove stubborn algae from the sides of the pond and/or rocks. Do not completely remove all the beneficial algae from the sides of the pond.
    8. Remove the sludge and debris from the bottom of the pond using a shop vac or broom and dustpan.
    9. Rinse the pond and drain it completely.
    10. Refill the pond.
    11. Treat the pond with the appropriate amount of dechlorinator and Stress Coat.
    12. To reintroduce fish, slowly add some of the fresh, treated pond water to the holding tank. The holding tank water temperature should be within 3 degrees of the pond water temperature before reintroducing the fish.
    13. Release the fish and scavengers into the newly cleaned pond.