Unknown acro dieing? UPDATE!!

[reeferRob]

I got home and noticed one of the branches completely or VERY nearly all white today. It had been doing better and starting to color up. I got this coral for free from a friend who let it turn dark brown, he says it should be purple w/neon green polyps. He got it free from Dr. Foster's due to the entire back half arriving white and dead, but I know if I can just revive it it will regrow. There is an acro crab living in it but thats good right? My paramaters are as follows:

SG 1.025
temp 78
Ca 420-450
dkh 10-11.5

I think it may be lighting, but I don't even know what this coral requires. I run 4-96W dual actinics from 6-12 am, 3- 150W XM 10k from 11-6pm, and actinics again from 5-10pm every day. When I first got it I was afraid to put it too close to the top right away so I put it about midway to bottom, almost directly under (but not quite) a halide, and like I said it seemed to be doing good and getting some color. Then when I get home from work today I see one branch dead.

I don't see any redbugs or other pests anywhere.

Any Ideas??
Thanks

Rob

Here is the same coral I posted in April that wasn't doing do well, it is now recovering and doing WAY better! Still has a ways to go yet though!