Help Possible humidity issue?

Hey looking for advice, this is not my first grow however it is my first in a very small area. I'm using a 400 w MH light with a 4 inch exhaust system that cycles my air around prob 2 times a minute. This plant is really making me scratch my head it just doesn't wanna play nice lol. First issue is I feel like she's barely drinking. Originally my issue was heat until I got the exhaust fan put in now my room maxes out at 85 for just a couple hours before I get it back down to 72 for the rest of the day. Her first visible sign of issue was slight clawing of the fan leaves. Note I have only fed 1 time at a very low dose of fox farm veg nute. My ph in soil was a little on the high side at 7.5 so I did a ph watering and got run off down to 6.2 and now the clawing is worse. I know clawing is tell tale nitrogen issue, but I have yet to really be able to feed her. The only thing I don't have track on is humidity which being in a small space with high intensity light im assuming it is extremely low. Any input is appreciated. I'm just trying to stop the claw and get her thriving. Thanks.