Tell me why I can't use MH/T5 lighting systems designed for hydroponics?

[RCFA]

I don't see why this would be a problem. I have a couple hydroponic systems and a reef, and there are only couple of key distinctions. Bulbs, and reflectors. My T5s for my hydroponics have significantly inferior reflectors than those on my reef and the bulbs are totally different (unless you are trying to grow a lot of macro you probably want different bulbs). Other than that, the T5s come in the same HO wattages that I use on my reef tank. One other thing to keep in mind when comparing systems, is that there are quality differnces in the componets such as active cooling, moisture resistant encaps and better quality ballasts that will all raise the price of reef lighting above hydro.