With Mh or any other light for that matter, do you keep the glass on the top of the tank or not? Basically is it alright to have the galss in between your lights and the water? Or does it even matter?
I have glass on top of mine because it keeps the fish in. I had my grouper jump out one time when I took off the glass to clean it. I guess he just wanted to be closer to me. :happyfish
Glass will reduce your light output and it will trap more heat. But you do need some sort of cover between your water and your lights to keep the salt spray from hitting your bulbs.
Use strong lighting and a chiller if you need to (I don't yet) if you use glass covers on your tank.