Is it light burn?

The irregular pattern of the damage says to ME that it is indeed some light burn... nitrogen toxicity starts at the tip of a leaf and moves inward - and starts on the lower leaves... calcium deficiency will begin as small brown dots ... so what your leaves are displaying fits neither one of these... You've done the right thing by moving your lights higher... just be careful when you water that you don't get the leaves wet and you should be fine. Good luck!