MH lighting setup

[usinkit]

I have purchased a 250 MH retro fit light to go with my 384 PC lighting on my 40. I would like to know what heigth does everbody keep them from the water surface. I keep my PC's about 6 inches off the surface. I know I will end up having heat problems but a few fans should take care of that. My main concern would be the corals. I have in there shrooms, zoos, polyps and xiena. Will I have to much direct light on them with the 634 watts? Should I just biuld another canopy to raise the height of the lights?
Thank you for any help.
Brian

 

[usinkit]

bump

 

[reefnut]

It's recommended to mount them 8-12 inches off the water.
Make sure you acclimate your corals very slowly to the new light.

 

[usinkit]

Thank you for the reply!!