Super NewBie.....PLS..HELP... Just Looking For Feedback...Any advice is good Advice

They are 2weeks old for seed.. They are in a 3x3x6 grow box under 400w MH/HPS HTGSUPPLY switchable lighting system. I made a homemade Co2 gernerator system... the temp... stays between 70-72 when lights are OFF and 89-90 when lights are ON On One of the plants its turning slightly brown and curling slightly. Pls Help...

Pretty hot in there. That might be why you are seeing the curling. 90 degrees is pretty warm.....it can be done, but my guess is that is what you are seeing.

One of plants showed brown curling leaves. I kinda freaked out and was told to wait it out and she turned out fine. Your plants look to be off to a good start tho