Yeah, T 5's and CFL combo would be great in your veg room, hes right even a 250 Mh will significantly add to the heat already put off by the HPS, youll have to really watch your humidity and temp if you do that. But CFL and t5 would be way more efficient for that area, make sure you ventilate extremely well, your gonna have to have air coming into the closet from a outside source also, is your HPS air cooled?