Help, please with LED light height

[Rlumenator]

I switched from comp. fl. to H4 LEDs, and am trying some sps corals. The lights are 9" above the tank, and another 9" above the top of the reef (rock) 18" total. Do I need to lower the lights, or am I ok here? How low can I place the acros at this height? Also, I have bright green zoos at the top that are developing brown centers- too much light? Thank you, Dawn

 

[trido]

I would guess that the light fixture is at a good height from what I've read on LEDs. As far as acro placement. Half way down? :? ?
And yes, the green zoas likely are getting too much light.