I adjust my 7.9 ph wellwater down to 6.9ish, then add the nutrients. Brings me down to about 6.5ish. But I feed twice weekly, at half the online dosage, (ends-up being the same weekly totals) so a full-dose of nutrients will bring the ph down a little further. With those color-coded ph test kits...after you add the nutrients, the color-coded results are skewed by the tinting of the nutrients. (extremely inacurate)

I've been using the FF line for years. Yes...half-strength at first and sneak-up on a maximum dosage. But for normal dosing, with sativa dominates, (which generally requires less nutrients) give a tad less than indicated strength or leaves can burn. For hearty indica domiates, follow their online weekly feeding schedule. (available at the Fox Farms website) Print it out for your convienence.

Until you get good at their trio and their schedule, I wouldn't use the soluables. They are powerful stuff, and can easily be misused.