height of light

[reef kid96]

I have been wanting to get into the sps part of the hobby so the first thing i did was go out and get a light, I got a giesemann infiniti with 2 ati blue plus, 2 ati actinic and 2 phoenix 250w 14 k bulbs. This will be going over my 90 gallon and my question is how high should I keep it above the water so I can grow sps on the middle up while not burning up my lps and softies on the bottom?
Thanks in advance Andrew