Are you misting the plants with the light on? If so then the light can magnify on droplets and burn the plant. Best to mist them when the light os going off. Could also be due to overwatering or your light being too close depending on the wattage of your led. I also noticed that you dont have your ppm or ph listed on your diary. It is usually easier to figure out the problem are experiencing if you monitor those closely. Good luck!