Howdy alltatup, Sorry to hear that You are having problems with Your grow. I have not used LEDs, so I do not know much about them, but since you are having problems only with the LED plants, could there be a problem with 'hot spots' from the LEDs? How are the temperatures (water and air) ranging? Is there aeration of the reservoirs? In the attached photos there seem to be places where light could infiltrate into the reservoirs. What is the silver bar like item on the right hand side in between the plants? If both of Your grows are setup the same, except for the lights, then I would suspect the lights may be part of the problem, either too close or too far away. On my CFL grows, I have noticed as the leaves grow on the upper portion of the plant, the lower leaves get 'shaded out', turn a slight shade of grey green, shrivel, and fall off.
It could be a simple thing or a combination of several things. Good luck and I hope that it clears up.