soil ph

I've been growing with Pro Mix HP for years now with excellent results. Recently I've noticed a change in their mix. Previously I've been adding Aluminum Sulfate at the rate of 3 grams per gallon to my mix to lower the starting pH of the Pro Mix. I had a grow where my soil pH was dropping...

Oh wise AFN canna gurus, I need some enlightenment. I just got my CWP pH8 soil meter. I have started testing soil in 3 of our girls so far (have a few more to test) about mid way down and all the way down and in 3-4 different locations in their airpots. We grow in FF Ocean Forest which is said...