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Camellanus Worm Treatment Information

This is a compilation of interesting and Informative Posts Found While Searching For More Information about the Camellanus Parasitic Worm Disease

Recommended Dosage of Levamisole Treatment

Dr. Roy Yanong, V.M.D. recommends the following for treating fish with internal parasites susceptible to Levamisole HCl:
"In answer to your question, the dosage rate for levamisole in a bath is 2 mg/L (2 ppm) for 24 hours (followed by 70-100% water change, and siphon the bottoms of the tanks), with repeat treatments necessary–retreat in 2-3 weeks, and probably one more time after that. This is regardless of size of fish."
The 2 mg/L dosage rate (of the active ingredient Levamisole) is currently (2007) the level being used by the scientific community. It effectively paralyzes Levamisole susceptible parasites at that concentration. Increasing the dosage level does not seem to have any greater effect. (Another good reason to avoid overdosing.) Paralysis of the worms takes place when that level of Levamisole is present in the host–your fish. Dr. Yanong recommends, whenever possible, trying to diagnose what parasite your fish are harboring prior to treatment. Work with an ‘exotic pet’ veterinarian, or a fish health specialist to insure you are treating with the right medication.

Dosage Calculation

Some helpful conversions:

For 100% Levamisole HCl in powdered form (Levasole, Soluble Pig wormer):

1 teaspoon = 4 grams
.5 teaspoon = 2 grams
.25 teaspoon = 1 gram
1.0 US Gallon = 3.78 Liters
Here is where our chemistry comes in.
The molecular formula for Levamisole base is C11H12N2S
The molecular formula for Levamisole HCl is C11H12N2S•HCl

Because we know the formula we can figure out the Grams/mole off the periodic table which is:

~204.32g/mole (rounded to hundreds) for levamisole.
~240.78g/mole for Levamisole HCl because of the HCl (hydrochloride) attachment.
The active anthelmintic ingredient is the Levamisole, not the Hydrochloride, so to attain a 2ppm concentration of Levamisole using Levamisole HCl we will need more Levamisole HCl because of the size (weight) of the molecule. For example, if we know we need 50mg (at 2mg/L this will treat a 25L sized tank, or about 6 gallons) of Levamisole base but we are using Levamisole HCl, to achieve the same concentration of the Levamisolebase we need to make some conversions which works like this:
For those of us with underdeveloped math skills (like me), chefkeith has come to the rescue. He has created a Dosage Calculator for powdered Levamisole HCl.

To calculate how much Levamisole HCl powder you need simply type in the size of your tank in either liters or gallons and the measurement in teaspoons will be provided.

If you have a large volume of water to treat use the stock solution calculator which works like this:

Decide the size of the container you wish to use to create enough solution to treat all your tanks. Fill with dechlorinated water. Enter the size of the container in ml into the "amount of stock solution" field.

Now you enter the dosage size you want. If you want 1/2 cup of this solution to treat 20 gallons of water, then enter 4oz in the "dosage size", then 20 gallons in the "amount of water to treat".

The calculator then spits out that you need .64 teaspoons of Levamisole HCl to be added to that 2 liter bottle.

You can adjust the Levamisole ppm however you want it, but the default setting is at 2ppm.
He also includes a helpful link at the bottom for locating Levamisole HCl powder.

then divide that by 204.32 (weight in grams of Levamisole)
to get moles which is 2.447.

Then because its 1:1 (1 mole levamisole each (basically)) you take
2.447 multiplied by 240.78 (so you get correct weight for added HCl)
and you get .0589g which is ~59mg.

Thus, 59 mg of Levamisole HCl is equivalent to 50 mg of levamisole base.

2ppm = 2 mg/L Levamisole base
which converts to:

2.36 mg/L Levamisole HCl or
~9 mg/Gallon or 90 mg/10 gallons

How do you know how many milligrams of Levamisole HCl you need? More calculating:

We need 2.36 mg/L (or 9 mg/Gallon) of Levamisole HCl to treat our tank at the recommended dosage.

If we measure our tanks in Liters:
2.36 x (the size of your tank in liters) = mg/L of Levamisole HCl to treat your tank.

If we measure our tanks in gallons:

10 US gallons = ~38 Liters
For a 10g tank that means:
2.36 x 38 = 89.68 mg or ~90mg of Levamisole HCl will treat 10 gallons with a 2 ppm concentration.

Going by chefkeith’s calculator a very small amount of levamisole powder is needed to treat a 10g tank (.076 grams, or .019 teaspoons). Now I don’t know about you, but I don’t own measuring devices that will enable me to accurately measure that tiny amount. Overdosing Levamisole HCl (even massively so!) has been common practice for a long time. However, adding more does not increase its effectiveness and can have negative effects up to and including death. Try to avoid it, if at all possible. The 2ppm dosage level will do the job.
Lacking the necessary tools, I generally eyeball my powder measurements into usable sizes. Since a quarter teaspoon is about 1 gram and we need roughly one tenth of that amount for a 10g qtank treatment I do the following:

  • Measure a level 1/4 teaspoon onto a smooth surface.
  • Take a razor blade and divide that quarter teaspoon into 10 even piles. Each tiny pile is one treatment for 10 gallons.
  • Store each tiny pile in tiny plastic baggies (or tin foil) with a ’10g’ label in an opaque container.

Not very scientific, I know. But it does get me close, and I am confident enough in the safety of the medication that I have no fear for my fish that a slight overdose will be dangerous. In fact, prior to this article, I had previously treated fish with Levamisole concentrations as high as 800 mg/10 gallons and saw no negative effects. That has not been the outcome in all cases (See "Comments" below). Overdosing is not recommended. Increasing the dosage level has no effect on the efficacy of the drug, and can be dangerous.
*For those who cannot access Levamisole HCl, Charles Harrison Ph.D. has a very helpful article on Flubendazole.
Flubendazole is an effective medication for Camallanus and other nematode infections and is adsorbed, rather than ingested. It is a good medication for treating fish who are no longer eating. It is available on order from his website:
It will kill snails, so if you have a thriving snail population consider removing your fish to a quarantine tank (without snails) before using Flubendazole. A large dead and decaying snail population will seriously foul your tank environment.


Levamisole HCl is a safe and effective anthelmintic for use in aquariums when administered in the proper dosage. It does not harm the biofilter, plants or invertebrates (including shrimp) in your tank and has the added benefit of stimulating the immune system of immunocompromised tank inhabitants. I highly recommend its inclusion in any fishkeeper’s arsenal of medications. For those of us who purchase wild-caught fish, it should be part of our prophylactic quarantine tank treatments for newly purchased fish.

Hobbyists have been using it for years now, and there are few reports of negative effects on fish. At higher dosages than recommended there have been some reports of cloudy water at initial treatment, and a very few reports of rapid respiration or stress related behavior in fish. I’ve also located a few accounts of massive overdosing leading to wipeouts in tank populations. One reported result of treatment stated yellow water, clamped fins and heavy breathing in cichlids, as well as explosive plant growth. After a couple of days, the negative effects on the cichlids seemed to disappear so he continued the treatment regime. I suspect the phosphate form may have been the formulation used in this case, but was not able to determine that definitively as I could not locate the drug he cited to find the information.

Dosing levels prior to this information were all over the charts. Almost without exception, the dosages used were higher. Some were much higher. Recommendations ranged from 1-2 mg/l up to as much as 21 mg/l. Based on the research for this article it’s my hope that hobbyists will face less confusion regarding the use of Levamisole HCl in aquaria.

Below is the treatment protocol I have used for treating parasites with Levamisole HCl. It is very similar to the treatment recommended by Dr. Yanong. Your mileage may vary.

  1. Determine the appropriate dosage for your tank.
  2. Treat with the lights off and increased aeration.
  3. Perform a largish water change prior to treatment. With my water supply I cannot do more than 50% without causing a tank crash so I don’t do the 70-100% changes recommended.
  4. Treat once for 24 hours.
  5. Do a largish water change and vacuum to remove any paralyzed worms in the substrate.
  6. Return tank to normal lighting/feeding/cleaning cycle.
  7. Treat again in 5-7 days after a water change. If you know the parasite you are treating and its life cycle adjust the timing for the second treatment accordingly.
  8. Do another water change with gravel vacuum.
  9. Return to normal schedule.
  10. Treat a third time 1 – 2 weeks after your second treatment.
  11. Do another good vacuuming with water change and consider your treatment complete.

Usually, a marked improvement in vitality and appetite will be observed following the first treatment. Don’t let this convince you that the fish is cured! Complete a full course of treatment. In commercial fish enterprises and in livestock there have been reports of various parasites developing resistance to Levamisole HCl treatment. If you see no improvement after the first treatment your fish may be suffering from a secondary bacterial infection caused by parasitic damage. Consider treating the affected fish in a quarantine tank with a good broad spectrum antibiotic such as Maracyn I and II, or Kanamycin.

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