Hey dude, I just wanted to pass on some information that I gained earlier today through Gastanker.
My leaves were curling up and turning a yellow brown, I originally thought it could be nute burn but it happened over a period of 20 minutes. I soon after found out that if you mist your plants with a water bottle and then put the light directly back to its spot (very close to the plant) even if its minimal heat it causes evaporation and could potentially strip the moisture from the leaves. My suggestion would be to leave your bulb as close as it is, but only mist your plants once right after the light goes off and goes to darkness cycle. My problem happened yesterday morning, I stopped spraying them and although I lost the fan leaves (mine were MUCH worse than yours cause of massive heat) I still have healthy plants.
So in a nutshell my suggestion is to stop misting/watering your plants until its the beginning of your night cycle.
EDIT: Keep in mind I am a first time grower, I tell you this because I had the SAME issue only it was worse. Your issue could be a completely different problem so dont quote me 100%, try it and if it doesnt work please seek other assistance.