About leaves mark yellow.

I'm having your same problem, at first I thought it was due to an excess of water, but, after a few days, I think it is a phenomenon linked to the life cycle of the plant. the closer you get to the harvest, the more the plant's forces are focused on producing flowers. So I would say it is a normal phenomenon in this phase of the plant's life. Good luck!

I agree with gmslave, possibly too much cal/mag. If you are using tap water and a decent grow/flower nutrient, this should provide enough calcium, however a slight boost once in a while during flowering is a good safeguard. On another item I noticed in your diary, I would recommend only removing old yellow leaves. The big, green, healthy leaves are producing the energy your plant requires to grow her flowers. Fewer green healthy leaves = less energy produced = slower growth. Hope this helps in some small way.... Organoman.