Blotches huh? That makes me think it's a pH issue gone overboard. We have to have more info to do you any good. I'm not being ass-ey, I hope it doesn't come across that way. But we really need more info at the very least, and lke others have said, pics are best.
Just some of the needed info:
What nutes...what doses...and how often....any amendments like
Superthrive?
How far away from the canopy is the light?
What are your temps and humidity?
Do you have any ventilation running?
Are you using CO2?
What size containers are they in?
I know it seems like I'm asking you a butt-load of questions, but we really do need to know as much as possible in order to help ya with the RIGHT diagnoses.
As it stands now, it could be pH, mag deficiency, nitrogen deficiency, light bleaching, massive overwatering, etc, etc.
Give us some more specifics and maybe we can get her straightened out.:flower