And to be honest there are not a many alkaline sources in the nutrients we use. So a buffered soil usually keeps its ph for as long as a grow goes atleast. Usually the issue is just that the makeups of fertalizer we use are generally acidic.
I agree with ya. Nutrients are generally acidic enough. It all depends on how you buffer the soil. High alkaline water source little bit of lime. Using RO you gonna need more. I think another reason ppl see different soil pH with same products. That and the same label doesn't mean it's going to be from the same batch.
Funny you mention nutrients being acidic. Foliage pro is not acidic enough to counter my well water if i add even 2.5 ml of protekt (silica). So now i have been adding 1 ml ph down to 2.5 ml protekt and 5 ml foliage pro to be about 6.3ph. And the pro mix stayed there to the end.