Planted Tank Guru
Join Date: Jun 2012
Location: Gainesville, FL
Endothermic reaction when mixing macros
I had to mix up some dry ferts today. I used different bottles that were thinner than what I had before. I added 5tbsp. of KNO3, 1 1/4 tbsp. of KH2PO4, 20ml Excel (mistakenly) and 300cc of water. When I shook the bottles to mix, it became quite cold ; 53F from 74F in fact. I never noticed this before (thicker bottles I guess). Is this caused by mixing the KNO3 with water or what? I know cold packs mix ammonium nitrate, potassium hydroxide and water which produces KNO3 and ammonia gas but not sure if it works the other way around. Just curious.