Hammer Receeding

[Seriak]

I finally found an orange hammer and got it home almost a week ago but it has started to lose some of its tissue. I think about half the wall hammer has started to show its skeleton. Is there anything I can do to stop this slow death or should I just pull it from my tank now. I don't see any brown jelly at this point and I do have it in a low flow area. All parameters are fine except Ca which is on the low side (350ish). All other corals are doing fine, atm.