I'm on my first grow and in the 3rd week and I am using MG. Everything has been going great until this morning I noticed some yellowing beginning on a few of my plants with a few brown spots. From what I have been reading, it is likely nutrient overkill with the MG soil. Any suggestions on how to correct this problem, I haven't picked up a pH tester, going to tomorrow, but any ideas would be helpful. thanx