There are so many different kinds of lights. Which kind do I get? MH, PC, VHO, ..?? How do i know which one to get? I want to do mainly SPS. Iv done a bunch of reading, but still don't know what to do. Right now I have a coralife PC 50/50, OHhh and its only a 36" , my tank is 48" ....a friend gave it to me to use till i buy a light. Its a 75 AGA with overflow. I have plenty of room to suspend lights not an issue. If i wanted to do LPS would I use different light?