Greetings,

Was wondering if anybody could help me with a small problem. I had previously stocked a mix of K2SO4 (50g) and MnSo4 (0.18g) in a small container for future dillution into a 500ml distilled water solution. It was stored in a dark place maybe for more than 4mos. and when I took it out I noticed the dry powder mix had turned into a brown color which was previously white. Is this still usable? I'm a little weary of using it now since it might have turned into something that is utterly useless for the plants as far as nutrient supply or worse it might already be toxic to the fauna. Need your help guys.