Potassium Permanganate (KMnO₄)

A powerful oxidizer used in koi ponds for decades. Effective in cold water. Easy to misuse.

What it is

Potassium permanganate is a deep purple crystalline compound used as a strong oxidizer. It reacts with organic material and exposed organisms while it remains active.

What it’s good at

PP is best thought of as a system-level oxidizer that also has parasite benefits. It is commonly used against exposed ciliate parasites such as Ichthyophthirius, Trichodina, Chilodonella, and Epistylis.

Cold-water use

PP is one of the few pond treatments that remains usable in very cold water, when many other medications are limited.

Notes on flukes

While PP can affect flukes at higher concentrations with repeated treatments, most keepers find targeted medications easier and safer to use.

Product sourcing

Potassium permanganate can be purchased in many places. Pond-specific formulations such as Aqua Meds Eliminate are intended to reduce unknowns related to grade, storage, and handling.