Algae problems: ALL--- Micro -algae and cyano-bacteria of any kind, stopped with in-expensive KMnO4 oxidizer.

[369Augold]

This has already been discussed by 369Augold, but lots of people still request help. Read the article, the answer is there!

 

[shred5]

Potassium Permanganate is a oxidizer.
Albert Thiel used to sell this stuff in the early days of the hobby.. I think it was called Redox +.
No different really than adding Hydrogen peroxide or using ozone in my opinion.