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What Are Anchor Worms?

What Are Anchor Worms?

A: Anchor worms are worm-like attachments coming from under scales, causing red spots on your fish. Despite the name, anchor worm is not actually a worm but a parasite. These white string-like worms and their larvae can be introduced to your pond when adding new fish or aquatic plants. Once the worms have attached to the body of the fish, red sores or inflammation may appear at the point of attachment.

Anchor worms on your koi, goldfish, or other pond fish is a troubling sight but very treatable. Follow these steps for treating anchor worms and preventing a future outbreak:

How to Get Rid of Anchor Worms

  1. Remove Worms
    If you feel comfortable handling your fish, you can use tweezers to remove the worms. Follow removal with medication to treat parasites.

  2. Add Anchor Worm Treatment
    KnockOut Plus is an all-natural pond treatment designed to treat all single-celled parasites and fungal infections.
    Microbe-Lift Fish Lice & Anchor Worm treatment is the most effective treatment for diseases of fish caused by lice and anchor worms.

  3. Perform a Partial Water Change
    We recommend a partial water change (25-30%) because these symptoms are commonly seen when water conditions are poor. Fresh, clean water means improved water quality, which ultimately promotes your fishes' wellness as a whole, in addition to treating anchor worms.

  4. Add Stress Reducer and/or Pond Salt
    Next add  The Pond Guy Stress Reducer Plus, which is designed to reduce fish stress and heal damaged tissue. Stress Reducer Plus forms a beneficial stress reducing slime coat replacing the natural secretion of slime that is lost when fish are handled, breeding, or under stress. Stress Reducer Plus also works to remove ammonia, chlorine, chloramines, and heavy metals, making tap water safe.

    Salt Bath: Pond salt is a form of pure evaporated sea salt that is commonly added to koi ponds to support fish health. In low doses, pond salt has many health benefits for your fish. Learn more about pond salt here.

  5. How to Prevent Anchor Worms

    The majority of common fish diseases can be prevented with routine maintenance such as partial water changes, water testing, proper filtration, aeration and of course population control. Oxygen is the lifeline to every ecosystem. Consider adding or increasing  aeration. Bottom diffused aeration is the most effective way to circulate water and increase oxygen levels. We recommend allowing no more than 1-2 koi or 2-3 goldfish per 200 gallons of water to keep your ecosystem healthy.


    Still have fish care questions? Contact us and let one of our pond experts answer all your pond and fish care questions.

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