Light Height

I have 2 Photon 32's going above my new tank (72x36x30), how far above the tank/water should i hang them ?
The tank is fowlr, but might one day have some corals in it.

Obviously there is more tank than light would i be better just dividing the gap into 3 ? so 2 inches between the edges and 3 inches between the centre lights ? (64 inches - 72 inches)

 

Seems like that should light the entire tank lengthwise pretty well but you would have some area in the front and back with less light.You also might need to use 60 degree optics for the light to penetrate the 30inch depth.

 

distance from the water ?

 

I would say 6-8" above the WL.

 

thanks