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.
- 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
- 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.
- Unplug and remove any filters, tubing or water features.
- Use a water pump or bucket to partially fill the temporary goldfish tank with pond water
- 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.
- Add the appropriate amount of dechlorinator for the tap water that was added.
- 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.
- Slowly pump the pond water out of the goldfish pond. Allow the goldfish to swim into the deepest part of the pond.
- 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.
- 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.
- 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.
- Hose off the pond liner and remove the dirty pond water. Repeat this until the liner is clean.
- Check for any pond liner damage and patch as needed.
- Fill the pond with a garden hose and add dechlorinator. Use water from the temporary goldfish pond to make the switch less stressful.
- Trim and divide the aquatic pond plants, replant the marginals and add the any aquatic floating plants into the goldfish pond at this time.
- Finally place the goldfish and other creatures back into the goldfish pond.