Might want to read this first:
From Nagarajan's webpage:
POTASSIUM PERMANGANATE
Effective, but potentially dangerous treatment for parasites. Potassium permanganate is a useful fish disease treatment; acting against a range of protozoan parasites including Trichodina, Costia and Chilodonella, as well as monogenean flukes Gyrodactylus (skin flukes) and Dactylogyrus (gill flukes). In addition to being an effective anti-parasite treatment, potassium permanganate can also assist with bacterial gill disease and bacterial disease such as skin ulcers. It will also oxidise dissolved organic matter, reducing the biological oxygen demand and improving water quality and clarity. It is a very good thing to have in hand. But can also be a killer for many plants. I have found that Amazon sword and Hygrophilla-difformis are quite safe with the use of KMnO4.
As with many disease treatments, potassium permanganate is not really a medicine. It is a caustic alkali that, at high doses, can cause serious corrosion of delicate tissues such as skin and gill. In ponds it works as an oxidising agent in a similar, although milder, fashion, to household bleach! It is a very reactive chemical, reacting with organic material. During such reactions the manganate ion, MnO4- loses two oxygen atoms and is reduced to insoluble manganese dioxide MnO2. The ‘lost’ oxygen atoms react aggressively with other organic molecules, altering their structure and properties. It is these reactive properties that kill bacteria and parasites such as Costia, Trichodina and flukes.
If the tank has any particulate organic material, such as algae, detritus, or dissolved organic compounds, then much of the oxidation reaction will take place with these organics rather than the parasites or bacteria we are targeting. For this reason potassium treatments will not be effective in green water. A better method would be dipping the fish in permanganate solution for a short period.
Tips for handling
Biological filtration systems should be isolated during treatment, as bacterial flora will be adversely affected.
Repeated treatments may result in cumulative gill damage
The presence of dechlorinator in the water will inactivate the treatment.
It is affected by light, so treatments are best carried out lights turned off.
It is best to give the tank a good clean and vacuum before treatment to reduce the amount of organic matter.
Potassium can kill a lot of algae, increasing oxygen demand, especially in warm water over eighty degrees.
It is is more toxic at higher pH. In alkaline conditions a solid precipitate of manganese dioxide (MnO2) can form on gills. This can cause respiratory problems by blocking the gills. Additionally, MnO2 is a strong oxidising agent and presumably in such a situation could cause other gill-tissue damage.
Its use against bacterial gill disease has to be balanced against the possibility of further damage from the treatment. It will assist by killing bacteria and parasites in the gills. However, in such situations the gills are often swollen and congested and if a manganate precipitate does form on the gills it could push the fish over the top. This is more likely in alkaline conditions.
It should not be mixed with formalin as this produces toxic formaldehyde gas.
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.
It can be neutralized by adding hydrogen peroxide. A recommended level of one litre of 3% hydrogen peroxide (mixed in 10 litres of water) will deactivate 20,000 litres of treated water. This quickly clears the murky brown water, leaving the water crystal clear. If too much hydrogen peroxide is used the unreacted residue action may prevent further potassium treatments for a day or two, so it is best to only use hydrogen peroxide at the conclusion of a treatment. If the water gets too murky between treatments (as would happen with a high organic content), hydrogen peroxide could be used to clear the water but it would be advisable to do a good water change before continuing treatments.
It is effective against smaller ectoparasites such as Costia, Trichodina and Chilodonella however its effectiveness against larger parasites such Gyrodactylus (skin flukes) and Dactylogyrus (gill flukes) is dosage dependent. At residual doses below 1.5 mg/litre, treatments against flukes are not likely to be effective. Short-term bath treatments at higher doses are liable to be more successful.
It can be a useful support treatment when treating bacterial ulcers; first by reducing any parasite load and secondly by reducing both the organic content of the water and the bacteria levels. Although it will assist in the healing process, it will not, on its own, cure ulcers.
Wear gloves when using potassium permanganate as it will quickly react with the skin leaving a nice deep brown colour that takes a few days to go away.
Dosage
Potassium permanganate is available in common pharmacies as powdered crystalline form and a solution can be prepared as and when required using a few crystals. It is not advisable to store it in light and also it will stain.
Tank treatments: residual 1.75 mg / litre. Effective against bacteria and parasites (not larger parasites such as Lernaea or Argulus ). Can be repeated every day – maximum 4 treatments. Once permanganate water turns brownish, make partial water change. Then repeat treatment till 4 treatments are completed. At the third and fourth treatments, the flukes, bacteria and fungi take a beating. A major water change suggested after 4th treatment with necessary Hydrogen-peroxide addition to remove the residual permanganate. Remember strong aeration and agitation is needed during the treatment.
Short term baths: Effective against bacteria and parasites (not larger parasites such as Lernaea or Argulus ). Can be repeated daily. Maximum 5 treatments.
Dips: - 20 mg / litre for 20 seconds. Said to be effective against Lernaea or Argulus. Dips can also assist in stubborn parasite cases. Highly discouraged - only use as a last resort.
