If they're fresh cuts(un-rooted), you may want to make a new reservoir for your buggy. Rot, unfortunately is normal for many, but not good. If they're rooted and your root mass is turning black or brackish you'll want to get an enzyme product. I suggest Hygro Zyme. Sensi-Zym or others will work too. That will eat away the dead matter on your roots. for the room, just use common sense and try not to complicate things by over thinking it. You'll want to grow short stout strains. Or veg very briefly, and prune and train your girls. Either way, you want to have a very shallow canopy because you have no photo intensity with florescent lighting. think of forming a nice carpet of flowers not much more than 6 inches deep... If your room feels too hot it probably is, get air into it, and out in the easiest manor that you see as an option. Cutting holes in the door may be better for you if your not good at doing repair work. (easier to buy a new door). Keeping doors open and having a fan blow through your undercarriage that then circulates the hot air out of the top of the closet may work as well. Your operation has a 1000 variables only you know. Try your best and improve.