Your lights should be fine, I have a 1000 watt MH and a 1000 watt HPS in the same hood, my plants are only 18 inches from the glass. My room is 6x5 and 6 or 7 feet tall.

My plants started doing that " wilt " and getting brown crap on some of the strains. Every strain I had reacted different but my problem was pretty much I didnt use a " mineral matrix " so I was lacking some key elements in my soil. Possibly are they running low on fertilizer? Anyways good looking grow , what day did you start these again? They look similar to mine , except my norther lights is almost 20 inches in veg :X