Max# I've seen is 13 points.
Go check your pH. I'll bet it's significantly out of range. You've got micronutrient uptake problems. Plus a few of those plants will want new, larger homes soon.
I just gave someone instructions for that, and his soil pH situation is similar to what yours seems to be, but not as extreme:
http://boards.cannabis.com/plant-pro...ml#post1781471