Potassium permanganate (PP) has been used in the aquarium hobby for decades as an external treatment for parasites, bacteria and fungi. It is a valuable treatment when used correctly, but it is not something to use casually. Good preparation, accurate dosing, excellent water quality and constant observation are all essential for safe treatment
The method below is simply how we use PP at Fintastic Studio. It is not the only method available, nor is it intended to replace veterinary advice. Always research thoroughly before using PP and never leave fish unattended during treatment.
*Potassium permanganate can be purchased from King's plant barn under - Wallys Potassium Permanganate.
PP Stock Solution
Using a stock solution makes dosing much easier and more accurate than weighing tiny amounts of PP each time.
Ingredients
*20 g Potassium Permanganate (PP)
*Water
Method
1.Weigh out 20 grams of PP crystals.
2.Using a funnel, add the crystals to a clean 1.5 L soft drink bottle.
3.Half-fill the bottle with fairly hot water.
4.Secure the lid tightly and shake vigorously until all the crystals have dissolved.
5.Carefully open the bottle and top up with cold water to exactly 1 litre.
6.Replace the lid and store the stock solution in a cool, dark place out of reach of children
Preparing a PP Bath
There are two ways we commonly perform PP treatments.
Bucket Method
1.Use aged water without dechlorinator.
2.Match the water temperature to the aquarium.
3.Add a heater if required.
4.Provide strong aeration using an air stone.
In-Tank Method
1.Thoroughly clean the aquarium first.
2.Remove as much organic waste as possible.
3.Turn off the filter during treatment.
4.Add additional aeration.
Organic waste quickly consumes PP, causing it to lose effectiveness.
Performing the Treatment
1.Prepare the treatment container or aquarium.
2.Add extra aeration before dosing.
3.Add the calculated amount of PP stock solution.
4.Observe the fish continuously throughout the treatment.
If any fish show signs of severe stress, such as:
*Rolling over
*Lying on their side
*Loss of balance
*Severe respiratory distress
stop the treatment immediately.
To end the treatment you can:
*Perform a large water change
*Add a neutralising agent
*Transfer the fish to clean water
Neutralising Potassium Permanganate
Several products will neutralise PP.
Vitamin C (Ascorbic Acid)
This is our preferred option.
A 50 g/L Vitamin C stock solution neutralises PP stock solution at approximately a 1:1 ratio.
Hydrogen Peroxide
Hydrogen peroxide works quickly but should be added slowly.
Stop adding as soon as the water changes from purple to clear. If necessary, more can always be added.
Water Conditioner
Dechlorinators containing sodium thiosulphate (such as Seachem Prime) will also neutralise PP, although they tend to be less effective than the methods above.
Tips for Success
From our own experience, these few points make a huge difference.
Have a backup plan
Always have a spare tank or container with clean, temperature-matched water ready before starting treatment. If something goes wrong, you'll want to move the fish immediately.
Clean the aquarium first
PP is consumed by organic matter.
If the aquarium contains waste, uneaten food or detritus, the solution will quickly turn brown and most of the treatment will have been wasted.
Don't use dechlorinator first
Avoid adding commercial water conditioners immediately before an in-tank PP treatment.
Most dechlorinators will instantly neutralise the PP, causing the water to turn brown almost immediately.
Use hydrogen peroxide carefully
Although effective, hydrogen peroxide is still a strong chemical.
Add it slowly and only until the purple colour disappears.
Never mix PP with formalin
Do not combine potassium permanganate with formalin.
The reaction can produce formaldehyde gas, which is hazardous and can severely irritate or damage the respiratory system.
