MH lights are great for getting your plants started in the veggie stage. They makes your plants short & stalky. Not good for flowering BUT you can get a HPS conversion bulb and put it in for the flowering period. You might have a heat problem if you put that thing in a closet. Be sure to provide plenty of ventalation. Here's my set up, a 400 watt HPS with a 280 CFM exhaust fan hooked to it.