I don't. I run metal halides. Know that a 4 bulb fixture wont be able to keep most acropora species really happy but you may be able to grow some easier sps. As for color combination, it really depends on what you light. I personally like my light a little more white than most. What lexusman25 suggested looks like a good color combination, althuogh I've heard that 3x ati blue + and 1 purple looks ogod as well.