uses:
-waterpurfication
-snow marker (big purple stain on snow)
-anti fungal
-firestarter

cons:
very hard to dose. Doses for water purfication is about 2 crystals per quarter (depends on the size). But very little actuall research has been done about the actually effectiveness of KMNO4 in killing waterborn organisme. May cause burns to you skin and will cause heavy damages to your eye's if it comes in contact with them, possibly blindness.