Leaves dying week 6 flower

an imbalance for sure... maybe you ddropped N off a bit too much? But, like i said in previous question, it's not quite progressing where it should be (bottom-up on plant) -- too much is up top. Shedding a few leaves buried at bottom is no big deal, but if it progresses beyond that, it is something that can be fixed. think i also mentione,d the unusual symptoms at top are alos the tallest cola.. might just be getting a hair too much light in that location. nutrients in leaves can't keep up with rate of photosynthesis in that location. nitrogen will be trucked in, but also not keeping up. you shoudln't drop N to "zero" .. this is where more info can help... fertilization is about the culmination of all you've done and not just what's been done recently. whatever ratio that fertilizer is.. it's just not good enough. when it's only 1 or 2 products it's tough to mix/match to get the right ratio - limited options. i like having N provided mostly from 1 product that way it can be easily reduced without changing levels of the other nutrients. Boosting p and k in flower is fine as long as you don't feed it too much early on, otherwise you end up with p and k tox. There's no simple answer with the info given... pick a path, don't over-do it and see whathappens. revert and try again if it doesn't slow progression or reverse it. it can take time to see results. if you react by doing multuple things, you'll never learn the cause and effect.