This is an EXTREMELY old article. But it was written during active fish medicine practice and had a high degree of success. I don’t dare change or edit it at this point because it worked as written.
Potassium permanganate Daily Regimen for Ciliates
Potassium Permanganate: An alternative method that works
Dr Erik L Johnson 5/19/96 (yipes!!)
Potassium permanganate KMNO4 turns the water purple while it’s working.
Recently, almost every publication has run some form of my recommendations on the use of Potassium permanganate. I expounded on two methods, one involved maintaining a pink water color with sequential doses over ten to twelve hours. This was extremely time consuming, and repeat dosing made a lot of folks very very nervous. The second method utilized a series of five jars, which were used to test the Potassium demand of the water, and allowed for considerable error in the form of under-dosage.
I have since (1996) been experimenting with a new method that works very well, and which has been verified microscopically by clearance of fluke parasites, under numerous conditions encountered in local (and national) pond situations. In other words, we treated a lot of ponds this way and results have been 100%.
Potassium permanganate is a caustic alkali that oxidizes organic molecules in water. In this process, organisms and bacteria are killed, which makes it an effective antimicrobial, anti-parasitic and molluscicidal compound. The POTASSIUM PERMANGANATE eventually converts into Manganese Dioxide and can be removed with water changes and filtration. We appreciate POTASSIUM PERMANGANATE because it is effective against waterborne bacteria infections, external fungal infections, all ciliate infections that are not encysted, all Trematode or fluke infections, and many others. The Potassium Permanganate does not do well against the macroscopic parasites like Lice or Anchorworm but these are quickly eliminated by Dimilin®.
Potassium Permanganate stains fabrics badly, and can stain human skin to a deep brown color, a staining that lasts up to 12 hours. Eye protection should be worn whenever this compound is in service.
To treat fungus, parasite, and bacterial conditions with Potassium Permanganate, several elements or steps of the new method need to be clarified.
First, bypass biologically active filter media.
Filter bacteria can be killed off by Potassium Permanganate and this can have deleterious effects on water quality. If the filter is small, flow rates are low, or fish are crowded or overfed, the effect is more pronounced than if the conditions are less loaded.
Second, make sure water flow and aeration are optimal.
The water needs to be aggressively agitated during treatment because as the organic molecules are oxidized, and string algae die off, water turbidity becomes threatening and dissolved oxygen can plummet. If you cannot hear the water circulating, splashing and mixing, then concern over dissolved oxygen should be great. You will lose fish.
Thirdly, apply 2-4 p.p.m as a single dose in the morning.
2 p.p.m is indicated when young fish, un-scaled fish such as Doitsu, or when Orfe are treated. Never treat catfish with more than 2 p.p.m. 4 p.p.m is a better dose for scaled Koi. None of the recommended doses will harm plants; you will be relieved to know. Many retailers use Potassium Permanganate as a dip for incoming plants to exclude snails and their eggs. To dose 4 p.p.m you could measure out 1 gram per hundred gallons. Alternatively, knowing that 6 grams fits neatly into a level, non-packed measuring teaspoon, you could dose with one teaspoon per six hundred gallons. Add the calculated dose to a bucket of pond water and mix to dissolve it. Once the solution is stirred up, distribute it all around the pond, but especially in the water returns to be sure mixing is good and complete. A fish can be clouded by the blast in the pond and remain unharmed.
Once in the pond, the Potassium Permanganate will begin to eat up (oxidize) organic molecules and debris, fish wastes and mulm, as well as string algae. It may only remain purple for a few minutes in heavily loaded systems. Once its energy is spent, the water will turn to tea, amber or orange, or even brown, and then you may go to the fourth step.
CAUTION: If the water turns CLOUDY brown – there are too much organics (dirt) in the system to proceed with the daily dosing. A larger water change will be needed, which will require dechlorinator to be used, which will INACTIVATE the following day’s treatment.
The fourth step is to resume normal filtration and optionally execute a partial water change.
The following morning you would execute treatment two, adding the calculated dose of Potassium Permanganate in a bucket and dissolving well. Add to the pond with even distribution after bypassing biological media and ensuring aggressive water circulation/aeration.
In treatment two, you should notice that the water remains purple for a longer period of time. The reason is that the initial dose of Potassium Permanganate has oxidized a lot of the mulm and organic loading of the system. Again, after the dose of Potassium Permanganate turns to amber or brown as viewed in a cup or bucket, then you may resume normal filtration and execute a partial water change.
The following morning you would execute treatment three, adding the calculated dose of Potassium Permanganate in a bucket and dissolving well. Add to the pond with even distribution after bypassing biological media and ensuring aggressive water circulation/aeration. This treatment lasts even longer, due to the reduction in system organics from the previous two treatments. You do not need to remain at pond side for the treatment, although someone should be attentive to resume filtration and perform a small water change once the compound has deactivated. It is usually this third treatment that begins to let the fungi and flukes in a system know that things are very wrong in Koi Ville.
The fourth treatment *usually* stays purple for over three hours. The fungi, bacteria and flukes during this treatment take a royal pounding. Fish are flourishing as the organic and bacterial load in the system take a dirt-bath. If the third or fourth treatments stay purple for longer than eight hours, then this is the last treatment; this is usually sufficient to eliminate Flukes in the serial treatment. For most people, however, the fifth treatment is the capper, and then they are done.
A major water change (40%) is suggested after the fifth treatment in order to help remove a lot of the leftover brown scum and oxidized material from the system. A 40% water change mandates dechlorinator and that is the “end” of active PP in the system and will prevent further PP treatment for 48-72 hours. After this change, you will smell crisp clean water, observe good color in the fish, frenzied feeding behavior, and really *white* whites as the fish enjoy the best water they’ve been in for years.