How to Treat Koi With Potassium Permanganate

Potassium permanganate, also known as KMnO4, is an oxidiser that is used in treating flukes, parasites, fungi, protozoans and bacterial infections in koi fish and ponds.

If you notice that your koi have skin ulcers, gill disease, protozoan parasites, or are suffering due to poor water quality, potassium permanganate may be an effective treatment for your fish. It can also be used to improve water clarity by oxidising dissolved organic matter in the water.

Disconnect or bypass any biological filtration connected to your pond or fish tank. Potassium permanganate will kill almost all bacteria (99.9%) that it comes into contact with and will ruin the beneficial bacteria colony in your filter.

Aerate your pond or tank with a bubbler or non-biological filter. Good aeration is necessary because potassium permanganate lowers oxygen levels.

Measure out the dosage of potassium permanganate based on label directions according to your pond or tank's water content. You'll need about one teaspoon per 1,000 gallons. Make sure the teaspoon is level and do not overdose.

Fill a bucket with the pond or tank water and mix in your pre-measured dose of potassium permanganate. Be sure to mix thoroughly.

Slowly add the water containing the potassium permanganate back to the pond or tank. Do not pour the water directly onto any of your fish. Treat for approximately five hours.

Check the water's colour. If it is still pink, pour two cups per 1,000 gallons of 3% hydrogen peroxide into your pond or tank to neutralise and deactivate the potassium permanganate. Do not pour directly on your fish.

Restart your biological filtration system after three hours.