I would recommend flushing w/ 35% H2O2 and applying cal/mag as a foliage spray to quickly correct the defiance. The leaf damage doesn't seem to start at the tip and radiate towards the center of the leaf leading me to believe this is cal/mag deficiency rather than overfeeding. Just my .02, hope it help. Good luck, let us know what you decide to do and post your results for others to learn from.
1tsp/gal 35% H2O2 for the flush, water until you have a minimum of 20% runoff.
1ml/qt of cal/mag for the foliage spray, I would add a drop of Ivory dish soap a wetting agent and apply to the underside of the leaves before the dark cycle. After your soil dries from the flush I would use half strength nutrients and begin supplementing the cal/mag at half strength as well.