[whatsinurblunt?]

okay not 100 percent here so i would keep researching and asking peer advice. however your undergrowth will yellow out eventually but thats when its in flowering stages of growth. could also have to do with you soil. i grew my current harvest all the way through growth with mainly flowering CFLs however a week before flowering i had a veging bulb also. seems also like alot of light for one plant. 100watts to 1 plant and 30-40watts per additional plant if there are more then one. ive never personally had an issue like that but the signs of curling and yellow discolor are usually sum^^^ of the problems above and this advice is to the best of my knowledge not researched before i posted however ive had 4 harvests now and alota research prior but those are my first guess Good LucK