dude did i read right you use advanced nutrients big bud because they have brought 1 out designed for coco aptly named big bud coco just ordered 1ltr myself dont understand all the technical stuff but might be worth a look:Sharing One:
Frustrating huh. I got same prob brotha..
I've read and also experienced led lighting to use more cal mag! Don't quote me but I believe I read that the led lack a bit of spectrum that Sun provides therefore it cause the plant to use the cal and mag to make up for the lost light spectrum maybe that's why your getting worse results closer to the led! And I would say maybe the calcium problem caused a p k lockout! But for the trouble an frustration ur dealin with they do look pretty good! I add 5 tbsp of dolomite lime to 5 gallon bucket of 50%coco 50%perlite and also pre rinse coco mix with 10ml of calimagic! Best of luck with the rest of this grow!! Cheers