Potassium Permanganate

Potassium permanganate, KMnO4, is not really a medicine but rather a caustic alkali that oxidizes organic matter. When sold as a powder, it is a purple crystalline compound with a metallic sheen. Potassium permanganate is widely used as a powerful oxidizing agent, as a disinfectant in a variety of applications.

It is often marketed in the fish store as a pond clarifier, and is useful in the fish room to reduce the organic load of tanks, especially those that have been overfed. The purple crystals in the LFS products are usually indicative of the presence of the compound. It's also used by retailers to treat plant arrivals, killing snails and parasites. However, the best place to acquire potassium permanganate in small quantities is the pharmacy or drugstore.

It is considered to be less toxic than most other treatments when used at the proper dosage. It is rarely administered correctly, either causing "burning" of sensitive gill tissues or it is so weakly applied as to be useless. Proper directions are given below.

According to the veterinarian Erik L. Johnson DVM (an authority on fish health), in an article titled "The Perfect Salt Supplement?" (http://www.arborman.com/ potperm1.htm), potassium pemanganate (PP) is the perfect complement to salt as a form of treatment for fish diseases. "Potassium permanganate can be extremely effective against Flukes, Trichodina, Bacterial Ulceration and Fungal infections. Since this spectrum fills in the gaps where Salt seems to falter, it should be considered highly as an excellent compound to balance with Salt in any well-prepared drug cabinet."

Chemistry

PP is a caustic alkali. It dissociates in water to form the permanganate ion (MnO4-) and insoluble Manganese dioxide (Mn02). The reaction releases two oxygen atoms that react aggressively with other organic molecules, altering their structures and properties.

It has been reported that the permanganate ion kills parasites by oxidizing their cell walls. The Manganese dioxide forms protein complexes that attach to the respiratory apparatuses of parasites, killing them.

Effective Against

PP is effective against waterborne bacteria infections, external fungal infections, all ciliate infections that are not encysted, all Trematode or fluke infections as well as others. Dr. Johnson lists some of the pathogens that PP is effective against, making the compound a very effective treatment when you are not quite sure of your diagnosis, or in the cases where the fish has secondary infections or parasitic invasions: Saprolegnia, Costia, Chilodinella, Ich, Trichodina, both Gyrodactylus and Dactylogyrus, Argulus, Piscicola, Lernea, Columnaris and other bacteria including Edwardsiella, Aeromonas, Pseudomonas, plus Algae and Ambiphrya. It is reported to be especially effective against Trichodina, and not as effective as praziquantel against flukes. However, there are certain diseases that only respond to PP when it is used as a dip (10-25ppm for 90 minutes): Argulus, Lernea, Piscicola, Costia and Chilodinella. PP is especially effective in the treatment of Columnaris, Aeromonas, Edwardsiella bacterial, and true fungal infections.

The United States Department of Agriculture has studied Potassium Permanganate. According to the USDA, Potassium Permanganate was found to be effective against ich (Ichthyophthirius multifiliis), the protozoan parasite (http://www.ars.usda.gov/ is/pr/2001/010821.htm). The compound was effective in treatments as low as 1ppm (parts per million). It was also found to be less toxic to fish in soft water than copper sulphate.

Dr. Johnson says PP is not effective against the macroscopic parasites like Lice or Anchor worm.

Dr. Johnson does not recommend that PP be used as dip because of the possible damage to the gill tissues.

Treatment Regime

Caution: Potassium permanganate is a strong oxidizing agent, a highly caustic, tissue-destroying chemical, and a poison. It is harmful by inhalation, ingestion and through skin absorption. It is an irritant. It is readily absorbed through skin. If you are handling the pure compound (rather than the watered-down medications), wear goggles, gloves and old clothes. Use proper ventilation. It can stain human skin brown for up to 12 hours. Do not expose guppies that have open wounds to potassium permanganate. In the U.S. it has been placed on deferred status by the Food and Drug Administration.

Caution: Do not use in conjunction with Formalin or formaldehyde as this produces toxic formaldehyde gas.

Dr. Johnson also warns that the dosage with this compound should be exact. It's toxic level is just above its therapeutic level.

PP usually turns from pink to brown when it is spent. One method commonly used to determine dosage is to take one liter of water from the tank and add 1 mg of PP every twenty minutes until the water retains a faint pink color. Alternately you can line up five or six one liter bottles and add 1,2,3,4,5 and 6 mgs to the respective bottles. The bottle that stays slightly pink and does not turn to a brownish color is the right dosage. You may need up to ten bottles.

Because PP acts on all organic material, it will not be effective against parasites or bacteria in a polluted tank, a green water tank or tank with a high organic load. It is recommended that the tank and filters be cleaned (but not disinfected) and the inside glass sponged. Then a 30% water change should be performed. Even so, it may take a third treatment before the PP is effective against pathogens.

Check your pH. PP is toxic in high pH water. Do a test with a tank of culls. If pH is too high tiny manganese oxide salts will precipitate out, which could plug the fishes gills and kill them. Carbon monoxide is one of the products of the oxidation process, as well as carboxylic acids. In high enough concentrations, these are poisonous. Also monitor your guppies, if they appear stressed or disoriented, neutralize the PP with hydrogen peroxide (1.3 ml of 9% hydrogen peroxide, for every 10 imperial gallons of tank water, treated at a dose of 2mg/l of potassium permanganate).

Philip Shaddock's Treatment Regime for Columnaris

Here is Philip Shaddock's recommended regime for curing guppies of Columnaris. Unfortunately the maker of the aquarium product containing PP, Aquatronics, is no longer in business. However, Jungle Labs sells a product called Pond Oxy Clear. If you cannot find the Aqua Brite product, substitute with the right dosage of another preparation. The method adds salt to the treatment regime:

1. It's important that you clean the filter, sides of the tank and the bottom of the tank before adding PP, as it will be used up oxidizing the organic material without ever getting to the pathogens. Activated charcoal should be removed during the course of the treatment. Do a 30-40% water change, making sure the new water is aged and conditioned. The new water should exactly match the parameters of the water already in the tank. The best method would be to add PP to a sterile tank.
2. Using Aquatronics Flukes Control or Aqua Brite (both of which contain PP), add about eight drops for 5 gallons. Also add one teaspoon of salt. (If there is already salt in the tank, do not use salt. It will probably be ineffective. This is a good reason why you should not add salt to your tanks when the guppies are healthy.)
3. A few hours later add up to four more drops.
4. At the end of eight hours, do a 60% water change and let the guppies recover overnight. Replace the salinity lost to the water change (2/3 teaspoon salt).
5. The next morning, add eight more drops of PP and 1 more teaspoon of salt. Wait a few minutes to check the color of the water. If it turns brown, add four more drops. If it turns pink leave it.
6. If it turns brown after a few minutes, add four more drops.
7. The next morning do a 33% water change and clean the brown residue from the filter. Add eight drops of PP and two teaspoons of salt (this replaces salt lost in the water change and brings the salinity up to the maximum 3 teaspoons for five gallons). The water will probably turn a pinkish brown. If it does not turn at least a little pink, add four drops more. If the water turns a nice pink color, leave it for eight hours and do a 30% water change. You can then follow up for the next four or five days with no additional salt or PP treatments and daily 30% water changes.
8. If the water did not turn pink, repeat the last step the next day, topping up the salt but not increasing the salinity.
9. If you are treating flukes, the treatment should be stretched out to five days. This covers the life cycle of the egg-laying species of flukes.
10. When PP oxidizes organic material, a reddish brown sludge muddies the water and eventually fills the filter, so you have to clean the filter after each major treatment.
11. The treatment will probably kill most of the bacteria in your filter. You will have to cycle the tank after the treatment regime.
12. Dechlor and Seachem Prime will inactivate PP. Hydrogen peroxide is also used to deactivate PP. However, it is not a good idea to use this method with fish in the tank as the precipitate formed may irritate the guppy's gills.
13. Andrew M. Lazur, assistant professor, Department of Fisheries and Aquaculture, University of Florida recommends 10 mg/L (10ppm) for a 10-minute tank treatment using PP (http://edis.ifas.ufl.edu/FA032). However, see the note above, where Dr. Johnson warns about damage to gill tissues at these levels. Dr. Lazur also says that four days should be allowed between treatment regimes, or the fish will be harmed.

Where to Get

Aquatronics Aqua Brite or Flukes Control contains PP, but the company is no longer in business. See the paragraph above for the method the author uses to treat tanks with this form.

Jungle Labs makes Pond Oxy Clear, which contains Potassium Permanganate. We have not used this product.

PP is available in a crystal or powder form, although it occasionally can be found in solution. PP in its powder form can be found here:

Drugstores Water softening companies Farm supply stores Local chemical supply houses Internet stores serving the ornamental fish market Making a Stock Solution Caution: prepare the stock solution in a well-ventilated area. Wear gloves. Avoid inhaling the powder. Where old clothes and wash them afterwards.

A stock solution is made by adding 22.8 grams of the PP crystals to 12 oz. of distilled water (or 64.25 grams per liter). Store the stock solution in an amber bottle in a dark a cool place. Use 6 drops of the stock solution for each U.S. gallon to achieve a 5 ppm treatment strength (1 US gallon = 3.8 liter).

Caution: PP stains the skin brown for up to 12 hours. It is a strong oxidizer. Contact with other material may cause fire. Spillage with other material may cause fire. Complete clean up spills. Keep away from open flame. When not in use keep in a tightly closed original container. Store separately from flammable material.

To neutralize your treatment tank, use OTC hydrogen peroxide: 1.3 ml of 9% hydrogen peroxide, for every 10 imperial gallons of tank water, treated at a dose of 2mg/l of potassium permanganate. However, be aware that hydrogen peroxide takes several days to dissipate from water, so do not use it in repetitive treatments. Only use it after the last treatment.

ANTIDOTE: If swallowed call a physician or Poison Control Center. Drink 1 or 2 glasses of water and induce vomiting by touching back of throat with finger, do not induce vomiting or give anything by mouth to an unconscious person.