Problems with browning tips ..new to growing MJJ

This is my first time growing, and My tips are browning any quick solution to solve this.
I am growing in a college grow box, it has 8 CFL bulbs, 12 site DWC system, could the lights be too hot..

There would be more damage along the sides of the leaf with heat stress, this looks more like a nutrient burn. What are you feeding at the moment?

My exact feeling, possible nute burn.

I see brown tips like that on my mothers when they're root bound but usually everything starts to yellow and the stems get very thin and purple. I have also seen that with over watering and root rot.