Garlic (Allium sativum), is loaded with medicinal properties, including antibacterial, anti-fungal, anti-viral and anti-parasite properties.  Garlic as been used in aquariums for quite some time for the treatment and prevention of fish parasites.  Several studies have supported its use for this purpose, claiming the ability to kill parasites and offering immune support to control and prevent them.  This study adds another parasite to the list of those vulnerable to the effects of garlic, skin flukes (Neobenedenia sp).

The results of this study reinforce the growing view that dietary supplementation of garlic extract is beneficial to fish health by conferring protection against pathogens. Feeding garlic extract to L. calcarifer for a period of 30 days significantly reduced infection prevalence (36 – 50% less) and intensity (50% less) in fish challenged with Neobenedenia sp. Both garlic diets conferred similar degrees of resistance to Neobenedenia sp. and fall within the range of garlic concentrations (0.5 – 30 g) shown to effectively prevent bacteria associated mortalities in cultured fishes.

The premise of garlic’s mode of action in preventing pathogens in fishes is not well understood. However, both crude garlic and pure allicin extract dietary supplements have been shown to enhance the teleost immune system by conferring direct antimicrobial activity to serum, increasing the number of leucocytes and by increasing phagocytic, lysozyme, and anti-protease activities. Of these immunoregulatory responses to garlic, lysozyme activity, a component of teleost mucus, has specifically been associated with innate immunity to monogeneans.

Using Garlic for Aquarium FishGarlic Anti-Parasite for Fish

Fish-keepers have been buying heat-processed fish food that contains garlic in the hopes of tackling parasites, but there is little chance that it has any effect.  Allicin is the active component in garlic tested for parasite control.  Allicin is heat-sensitive, which means it loses it’s medicinal attributes quickly when exposed to high heat.  Fish pellets and flakes are almost invariably processed at very high temperatures, rendering any allicin content useless.  For that reason, the pelleted food used in this study was made in the lab and cold-extruded.

Our aquarium fish receive their garlic supplements primarily through Bottom Bites fish food.  They’re gently dehydrated at a very low heat to preserve the nutritional and medicinal properties offered by the premium ingredients they’ve become known for, including garlic. Real, whole foods and a proprietary herbal blend enhance and supplement the fresh garlic & allicin extract they contain.  They include other natural anti-parasite ingredients, as well as ingredients that soothe and heal the parasite-ravaged digestive system.

Garlic is an attractant, meaning it stimulates feeding and appetite in aquarium fish (unlike synthetic anti-parasite medication).  We use this to our advantage by soaking seaweed flakes in homemade garlic extract for fish, which makes it more appealing to species that don’t normally care for seaweed.  Combining garlic with seaweed results in an unbeatable weapon against fish diseases (both have antibacterial, anti-fungal, antiviral and anti-parasite properties) while also offering premium nutrition.  Seaweed boasts more bio-available nutrients than any other class of food, giving the parasite-starved fish a badly needed boost in nutrition while also providing fiber to help expel the parasites.

DIY Garlic Extract for Aquarium Fish

  1. Peel the number of fresh garlic cloves you require (1 pound of cloves produces approximately 1 gram of garlic extract, which you will then dilute).
  2. Press the cloves with a garlic press.
  3. Put the pressed garlic into a food processor.  Process until the ‘garlic juice’ is visible.
  4. Strain through fine mesh & add the liquid to the extract you made with the garlic press.
Allicin Fish Food Parasites
Look for clearly stated Allicin content if you purchase garlic supplements for your fish.

Garlic extract can be kept in the refrigerator for up to a week in an airtight container.

You can use extra virgin olive oil to dilute the garlic extract for it’s added benefits if you are adding it to a homemade fish food recipe.  If you’re soaking fish food, you may prefer to mix with dechlorinated water to avoid an oil slick on the water surface.  We do not recommend using full-strength garlic extract for fish.

If you decide to use pharmacy allicin supplements for your fish, make sure they state the allicin content on the package.  Avoid those made with aged garlic as they are considerably less potent. You can also purchase garlic extract for convenience.

Caution:  Using too much garlic may irritate mucus membranes.  Daily, extended use of large amounts may cause anemia due to iron-binding.

For more about naturally treating parasites in your fish tank, check out the post Natural Prevention and Treatment of Aquarium Fish Parasites.

??? Have you used garlic to treat fish parasites?  Please share your experience in the comments below.

Militz, Thane, A. et al. Dietary supplementation of garlic (Allium sativum) to prevent monogenean infection in aquaculture. 2013.


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7 thoughts on “Study: Garlic Fights Fish Flukes (With DIY Garlic Extract Guide) ©


  2. I’ve been feeding garlic to my saltwater fish since the 80s. It was quite a common practice for saltwater before freshwater got into it. It works, no doubt about it. Great article.

  3. I give my livebearers and cichlids your food and frozen fish food from the store so I guess I’m covered. And vegetables. I don’t remember the last time I saw parasites except in quarantine with new fish and now I know why. Thank you for spreading the word!

  4. NOT IMPRESSED that I’ve been spending extra money on fish pellets with garlic when it doesn’t even work!!! That should be false advertising!!! I’m going to try making my own fish food, it will be cheaper anyway.

  5. I tried bottled garlic but I didn’t use it very often. It’s a pain. My fish eat Bottombites two or three times weekly and they’re healthy as seahorses. It’s just easier to give it to them in food and I wish someone would come up with garlic flakes that actually worked.

  6. Garlic is a powerful additive but not safe for dogs. I gave up on fish because they kept getting sick and now I wonder if parasites were the problem. I’d love totry again…maybe I will. Thanks I think :-P.

  7. I heard somewhere else that garlic fish food is a ripoff. Thanks for verifying. I use garlic soaks that I buy at the fish store but they’re expensive. I don’t see any allicin measurement on the bottle. I’d like to try making my own.

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