What's at 2 degrees? GH or KH? GH or general hardness if too low indicates a lack of calcium, magnesium, or both. Plants need those two minerals to be healthy. If KH or carbonate hardness is too low (less than 3 degrees) pH becomes very unstable and can crash to very acidic.
I would test for GH if I were you. You might want to raise your KH a degree just to be on the safe side. You can use baking soda to raise KH, but I can't remember the dosing formula. Anybody remember how much baking soda rasies 10 gallons 1 degree?
