I have a 400w HPS, it is NOT air cooled, meaning it does not have a big hole exit the heat. Its a Sun System. It has some vent slits in the side and the top, and can have a piece of glass. It doesnt have the piece of glass and never has since my ownership. I was wondering if I should get a piece for it? Will it reduce heat underneath enough to make it worth it? Is there a chance the bulb will explode from overheating? Exploding bulbs is my main concern, never had/seen it happen but I know it does and it worries me. Im really just looking to get my plants closer to the light without buying a whole new hood, and without risking an exploding bulb.