Perpetual Dual Cab, 400x250w MH,Aurora B x The Pure x Dank Bagseeds. Enter The SOG...

My ph dropped to 5 late in flowering how can I avoid this in the future?
FFOF soil is what I use.

stop using so much N in flowering.... get fets with an N content of 0... like 0-15-10

Something must have been added to make it drop. You could probably use lime to raise the pH but 5 is not bad.