m0useanswered grow question 3 years ago I was under the impression PH perfect line was designed more for a coir/hydro setup not a soil based one? better cheaper options out there for soil growing.
Also they have many formulas for PH Perfect, cant tell what one your using, this questions is not linked to a diary. needs more information.
I'd say use their feeding charts online and pay attention to salt buildup in the pot. may need to flush it as its soil vs soil-less coir or hydro.
big bud is compatible with all ph perfect line ups. and says 2ml/L for weeks 2,3 and 4 so that's simple enough.
https://www.advancednutrients.com/nutrient-calculator/
they also have an app that would probably be up your alley,