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Homemade Defoamer for a Pond

Kimberlee Leonard

Pond foam detracts from the tranquil water setting intended. Foam is created by dissolved organic compounds rising to the surface through aeration. Foam levels increase when fish or amphibians are spawning or when the fish population has a problem with infection, parasites or viruses.

Foam production also increases when excess food or dead organic matter accumulates and decomposes in the pond. Reducing foam not only restores your pond to its aesthetic beauty, it protects wildlife from illness and suffocation. Defoaming the pond yourself requires cleaning up, doing health check-ups and adding fresh carbon to neutralize the decomposing material.

  1. Skim the pond with a bucket to remove existing foam.

  2. Pump air into the pond to pull more dissolved organic carbon to the top of the water, skimming the excess foam created through aeration.

  3. Clean any debris in the pond such as dead brush or fish. This reduces the amount of decomposing matter that contributes to creating foam.

  4. Look at the fish to make sure they are active and appear healthy. Lethargic fish or discolored specimens suggest medical care may be in order. Contact your local aquarium expert for an evaluation.

  5. Place activated carbon in mesh bags to reduce foam. Use 1 pound of carbon per 1,000 gallons of pond water.


Activated carbon is also called lignite. Replace carbon every six months to keep the pond at optimal oxygen levels. Only feed fish what can be consumed in five minutes. Any more than this leads to food rot.