Amount of time needed for MH

[jmbono]

What is the minimum amount of time required by MH'S to be efficient in a reef tank? I'm currently running 2-175W Sunburst bulbs for about 8 hrs (12 noon - 8:00pm). Could I cut that time down or would that be a problem? I only have a couple of sps frags; mostly soft corals and fish.:beachbum:

[Pete Jaenecke]

I also have 175w 10k mh lamps above my 125gl reef iwas told you dont need to run them 8hr a day, but?? iwas also told you should run them 12hr a day if you want, e-mail me and we will talk