MH lighting help

Hi, you may recall i had a problem with some corals bleaching awhile ago.  It was tough to know if it was because my magnesium was really low or because my lights were too close to the water.  My lights were only 3 inches off the water.  I've since raised my lights to 6 inches off the water.  Is that still close?  I'm still having problems with some bleaching on a chalice and pink birdsnest.  I have them really low in my tank.  I have another post going where i'm still having problems getting my Mag correct.  Should I try to raise the lights another 3 inches or do you think it's the water quality giving me a hard time.  My green slimer and superman coral look great although I have them really low.  The tank is a 90 gallon with 30 gallon sump.  The lighting is 2 150w mh and 4 H5TO.  Thanks for your help.

Edited by jw3571 - April 02 2011 at 7:46pm

I would shorten the photo period on the MH lighting to 4 hours for a week. Keep the T5s going the full 10 to 12 hours and then increase the MH 1 hour per week till you have them going for 8 to 19 hours a day. This should help the corals adjust to the light. Once they are acclimated to the increased light of the MH they should be fine.