Needs more N or is this just a pH problem?

Would say you have complete neut lock with ph 7.8 basicly doing a flush adjust ph till desired and check run off has same will start uptaking neutrients again once corrected

I'll agree with Creepy_Steve here but disagree with him only in one aspect.... this is not a nitrogen deficiency but a PK deficiency... at that high a pH, those two are going to be locked out...

check your pH but looks like a simple N-deficiency.. no coinciding symptoms or issues otherwise, eh? pH is more often the cause of a smorgasborg of symptoms. same with lockout due to one molecule being in too high of concentration to others. usually see confusing symptoms in this case of multiple thigns going wrong. This on the other hand looks like simple symptoms that progress bottom-up on plant (mobile) and from teh tip of the leaf in to center... almost cetainly nitrogen deficiency. A slgithly higher pH actually helps Nitrogen availability, too... 7.5 range won't lock out Nitrogen. Nonetheless, i'd still work on getting that back down to <7pH. I'd guess he's following some feeding schedule that has reduced N too much for bloom phase. unlike what the peanut gallery says, the plant still needs nearly all teh N you provide in vege while in bloom. The most i've ever had to reduce M is 10-15%... and many never needed a change at all - no tox or def symptoms. if symptoms show up, that tells you rate of what you provide is not matching rate of use... i didn't overfeed N becasue it never got lush and glossy or other symptoms of N-tox. read and react to plant above any so-called norms or guidelines that are often not based on science (deductive reasoning) and when they are not applicable/true in real world cases. observing cause and effect > culturally constructed nonsense.