AsNoriuanswered grow question 4 years ago For me biobizz works great, if you follow theirs dosage always bumps into 6.6
But when i use different amounts or lighter feeding i have to use ph down from time to time. Biobizz have their own up and down, i doubt that they would sell product, which doesn't work in full range.
MrGrowit had a video recently on youtube, how to reduce damage, just by diluting in smaller container and only then adding up or down to your feed bucket/tank