Hi all, got a tangerine dream clone that started 12/12 cycle on 2/8/12 when it was 20" tall to top node. Two days ago some new growth and leaves near the top turned white with green centers but mostly white. (pic below) Here's some stats from todays readings with oakton pcstestr 35... 5.88 ph at 71.6 degrees f, cond. 1214us, tds 861ppm, salt 685ppm. This is for the time being only affecting 1/2 of the plant and I am using a 4 color led 300w light using 2w diodes. The mother is fine and 2 weeks away from harvest. Used the same nuets in both grows (Botanicare pure blend pro grow & bloom). Only difference being the clone under leds and the mom under 400w hps. It looks cool but I'm sure its not doing the plant any good. Any help will be greatly appreciated.
You have a zinc deficiency. Zinc def show as interveinal chlorosis on the upper leaves. Mg on the older leaves, same symptom. You need to add a fertilizer with well balanced micro nutrients. PW