I am not knowledgeable on any organic PHing solutions, I just use the General Hydroponics ph down, 2 drops in a gallon of water throws me right in the 6.3 ph range and I run with it.A valid question for sure, I was hoping CoM figured the amount within the soil would carry it through? All the more reason we need to act as Guinea pigs and test their nutrient schedule on a 15g. To be true to their recommendations I think I would have to PH my RO water, what’s the best organic ph up for the job? Or should I try just RO?
I did my last grow with Acadia Spring water and that stuff ph's at 6.2 right out of the gallon jugs with a 120ppm.