Need Serious help big problem

So i have no idea what this is or whats happening but please i really need help someone this happen to a plant i had a while back and it died i dont want this to happen does anyone have any idea whats going one or what on my plants there in flowering and the fan leaves and leaves comes of buds seem to be going brown and flowering has to be slowing down.

What fertilizer do you use and how much? What is your PH? My plant had leaves like that and it was nute lock out due to high PH

Ive been using foxfarm big bloom and tiger bloom i also water and flush with molasis