How to Keep Fish Pond Water Clean

Updated November 21, 2016

Fish ponds lend beauty and tranquillity to a backyard, and lounging beside one can be the ideal way to spend a relaxing evening. But those moments of peace and relaxation come with a price: Cleaning and maintaining that pond. Fortunately, mucking out your fish pond isn't too difficult, and a clean pond will make life much more pleasant for both you and its inhabitants. Cleaning should be done at least a couple of times a year, and some pond owners recommend performing this task three to four times annually.

Transfer all fish and other living creatures into a baby pool or holding tank, wearing rubber gloves so as not to come in contact with bacteria during cleaning. Use a bucket to scoop some of the pond water into the holding tank, then continue to drain out more of the pond water so that the fish are easier to catch. Scoop them into the net and place them in their temporary tank.

Remove any pond plants and set them aside in flower pots until you replant them. Clean off any algae by spraying them gently with a hose. Take out decorative rocks and spray them clean as well.

Spray off the pump and filter with the garden hose, replace the batteries if necessary, and check the hoses.

Vacuum debris and excess algae from the pond, paying careful attention to the bottom, because sludge can release nutrients that encourage the growth of algae. Scrub the lining of the pond with a brush.

Replace the filter, pump, plants and rocks. Refill your fish pond with non-chlorinated water.

Add your fish and other aquatic creatures back into their freshly cleaned pond. Do this slowly, as your fish will need to adjust to changes in the newly cleaned water. Another way to help your creatures acclimate is to gradually add some fresh water from the pond to their holding tank as you clean. They will have a chance to adapt to changes in pH balance and temperature, and you can reintroduce them to the pond easily, needing only to top off the fresh water you removed earlier.

Maintain your clean pond by checking the filter periodically to be sure it is working properly. Consider using a biological or "bio" filter and an ultraviolet clarifier to keep the pond free of algae. If you are seeing less water flow on the outlet side of your filter, it may need a thorough cleaning. The filter sponge may also need to be replaced. Every pond is different, but the sponges typically last about two years.

Skim the pond for detritus every few days. Filtration systems rid ponds of much of this type of waste, but skimming takes care of the bits your filter may miss.


If you are filling your fish pond with city or county water, you may need to use a dechlorinating agent to keep the water pure. When removing plants from the pond, any delicate ones that depend on water can be put into the baby pool or holding tank with the fish. Consider fertilising the plants while they are out of the pond and easily accessible. This is also a good time to prune them, if necessary. Keep wildlife at a safe distance from your pond. Not only might they eat your aquatic creatures, but if their faeces get into the water, it can act as a fertiliser, causing more algae to grow. Select fish that like to eat algae. Several species of plecostomus, for example, along with Chinese and Siamese algae-eaters, will help your pond stay algae-free and will get along with most other creatures. Certain plants might also help to maintain your pond's cleanliness, but which ones you select will depend on the fish you stock. Planting greenery around the pond's edges can help filter dirt that otherwise may wash into the pond.


Be careful when cleaning the sides and bottom of the pond. Many people use water only because the chemicals in soap can change the pond's chemistry.

Things You'll Need

  • Baby pool or holding tank
  • Rubber gloves
  • Bucket
  • Skimmer or fish net
  • Flower pots
  • Hose
  • Wet/dry vacuum
  • Scrub brush
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About the Author

Based outside Pittsburgh, Jamie Rankin began her career as a professional writer as a news and sports journalist with the "Daily Courier," a subsidiary of the "Pittsburgh Tribune-Review." Her work has appeared in both publications. Rankin, who holds a Bachelor of Arts degree in journalism and communications from Point Park University, has been writing sports and pet-related articles online since 2004.