It's not possible to tell from the leaf photos whether it is a light or watering problem. I suspect the problem is that you were letting it get too dry and after a while, it started to deteriorate. Coincidentally, that deterioration happened about the time you changed the light source and increased the water. It is not likely that those changes CAUSED the problem. However, not knowing the specifics of the LED grow light, it is possible that is part of the problem.
You had success with the fluorescent bulb so I suggest going back to it. More importantly, water thoroughly until some water trickles through the drain holes every week or so or when the top 2-3 cms. are dry.