Have issues with the of BioBizz Grow dropping PH o...

Also not correcting PH from 4.5 and 5 didn't hurt the plant and the growth of buds was good. runoff ph was around 5.9-6.0. I am confused cause there is a lot of info on the internet that pH-ing in soil is not needed and also that ph-ing biobizz nutrient range is not needed. By everything that I learned in the last year doing this hobby, I should try to still ph to 6.5. I am also thinking that maybe my batch of BioGrow is somehow different or faulty cause its weird to me that dropping 6 mL of Biogrow in 3L 7-7.5 water drops it to around 4.5-5 PH.