Feeding a perfectly balanced solution at the wrong pH still starves the plant, because uptake for individual nutrients narrows sharply outside the usable band. Target ranges for soil, coco and hydro, with the lockout symptoms each produces, are listed at https://potentthcseeds.com. Soil sits comfortably around 6.3 to 6.8 while coco prefers slightly lower. Cheap pH pens drift badly and calibrating monthly is not optional.