How high is "up"?

[thegrimreefer]

OK,
Given 400W MH in full size luminarc III reflectors, with the glass at the bottom of the reflector (to close it off for the forced air cooling/AC kit), with three of these lights over a 72" long tank, 28 inches front to back, and a water depth of 25-26 inches....

How high over the water surface should I position the lights, say in terms of water surface to bottom of reflector/glass?

Thoughts?

R

[spsick]

depends on if it's an in wall setup, canopy, will the lights be moveable for access? I would say 8 inches minimum, a few more if it's possible.

[thegrimreefer]

The lights are hanging from the ceiling, so I could go up well over a foot, if need be.

The tank is in-wall, so there's no concern there about the lights interfering with viewing / glare.