Buds' leaves turning yellow/ white...

Hey friends. For a while now iv noticed that some of the leaves on my buds are turning very light. I am flowering under a 400w HPS and growing in soil. I increased the dosage of my (organic) nutes, because I think this is some defficiency? Or could it be heat? (doubt it though, got lots of airflow)
What is causing this and should i be worried?

thanx


Oh, and any idea how long till harvest?

hmmm its hard to say, what does the rest of the plant look like?

Rest of the plant is kinda turning yellow from the bottom up ;( I know it's normal for flowering, but I think this is a little too early.

definitely dont think it's heat because of the way the tips aren't curling down. EVERYTIME i have a heat issue (not just with MJ, other plants as well) the tips curl downwards and almost roll up like a burrito. I'm no expert but it almost looks like either a lack of nitrogen (which it shouldn't be at this stage) or maybe chlorosis? idk what could be causing it, look up chlorosis, seems like that's the closest thing i can find explaining it. however i have no idea what the cause could be... goodluck with that baby..... and harvest time..... who knows, it would depend on a ton of things... got a plant outside that's at 2 months now and it still looks like it has another 2 weeks or a month to go, and the one inside is a week into flower and it looks like it could be done in a month! all plants vary... in a guestimation i'd say a month. but a handheld microscope/loop that you can view the trichomes closeup would solve that issue for you! goodluck!