How to Clean a Goldfish Pond

How to Clean a Goldfish Pond

It might be time to clean a goldfish pond when its surface and margins are overgrown with aquatic plants (floating and marginals) and the bottom substrate is covered in a thick layer of dead or rotting debris. Not only is this unsightly, it can also affect the water parameters in the goldfish pond. Oxygen levels can decrease due to a lack of open surface area and all the rotting organic material can cause the pH to drop to unsafe levels. If the pond goldfish are breeding, the pond might also be overstocked, making it a good time to thin the goldfish community.

The best time to clean a goldfish pond is in late autumn when the pond plants begin to die-back after the first frost. The cooler temperatures in the fall will be a benefit since the pond water will be cooler and contain more oxygen. Early Spring before the breeding season is also a possibility.

Clean A Goldfish Pond
Prepare by gathering the necessary supplies
  • A large holding tank for all the goldfish
  • A garden hose with a spray nozzle
  • Enough dechlorinator for the water change
  • Water pump or a clean bucket
  • Aquatic plant baskets for plant division
  • Aquatic potting mix
  • Rubber boots or hip waders are recommended
  • A patch kit incase the liner is damaged
  • A dust pan and brush to clean the debris off the liner

Cleaning a Goldfish Pond

  1. Set up a temporary goldfish tank for the pond goldfish in a shady area. A small plastic swimming pool or a few Rubbermaid containers should work. Consider caring for goldfish by adding an airstone of a filter to circulate the water.
  2. Unplug and remove any filters, tubing or water features.
  3. Use a water pump or bucket to partially fill the temporary goldfish tank with pond water
  4. Fill the rest of the temporary goldfish tank with tap water. Stop short of filling the entire tank to keep the goldfish from jumping out. This will help the goldfish adjust to the new parameters of their water. Make sure the pH in the goldfish pond water and the water in the temporary goldfish tank is within .5 of each other.
  5. Add the appropriate amount of dechlorinator for the tap water that was added.
  6. Remove the floating aquatic plants and the planted marginal baskets from the goldfish pond. Place them into another holding tank or in a shaded area.
  7. Slowly pump the pond water out of the goldfish pond. Allow the goldfish to swim into the deepest part of the pond.
  8. As the goldfish pond gets low, carefully collect all the living creatures and place them into the temporary goldfish tank. Use a wet fish net or a small bucket.
  9. Clean any gravel substrate by rinsing it off in a strainer with pond water and placing the clean gravel on a sheet of plastic or in a container.
  10. With an empty goldfish pond, use a dust pan and hand brush to remove the layer of decaying organic matter from the bottom of the pond. Be careful not to puncture the pond liner.
  11. Hose off the pond liner and remove the dirty pond water. Repeat this until the liner is clean.
  12. Check for any pond liner damage and patch as needed.
  13. Fill the pond with a garden hose and add dechlorinator. Use water from the temporary goldfish pond to make the switch less stressful.
  14. Trim and divide the aquatic pond plants, replant the marginals and add the any aquatic floating plants into the goldfish pond at this time.
  15. Finally place the goldfish and other creatures back into the goldfish pond.

Reviewed By: Tim Winter

Tim Winter has a strong affection for pets and wildlife. His years of experience caring for various types of pets has led him to share his knowledge with others on the best practices in pet care. Tim holds a Bachelor of Science from the University of Oregon School of Journalism and Communications.

7 thoughts on “How to Clean a Goldfish Pond”

  1. My goldfish feed off the pond scum. I need to clean the pond because we can hardly see the fish now however I am worried about removing all the scum and then there isn’t anything for them to eat. Any advise? Thank

  2. Could you please tell me what we’r doing wrong! We clean our filter and it looks good one day then the next the water looks muddy again. What are we doing wrong?

    • That could be a lot of things. It’s really hard to tell what it can be based on the information you provided. It could be the mud on the bottom of the pond getting agitated by the goldfish as they search the bottom for food or the filter outflow can be pointed in a spot that hits muddy bottom or sides. It might be time to clean the pond’s bottom and remove extra debris.

  3. I have two goldfish ponds made of concrete walls and earth ground the size is 19ft.33ft.2.4ft and 11.100 glns aprox each.
    How should i prepared my ponds before cultivate or introduce the fish in it. in order to ensure the proper sanitation state and evironment for them.

    thanks a lot for any assistance.
    David Roman.


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