I am going to go on the assumption that it is Eunicea and start in that direction. If it starts to wither, then I can post up and hopefully someone here will have the answers.
edit : this is the best bit of info I could find on this:
The appearance of Eunicea is highly variable, with many colors within a single species. However, gray and brown shades are the ones most commonly seen in the aquarium trade. Captive Care: It does not appear that all species are symbiotic, and Eunicea, in general, have a reputation of being difficult to maintain in captivity. Certainly this is true for any aposymbiotic species. Eunicea are predominantly shallow-water corals, so strong lighting is necessary for the photosynthetic species, with strong indirect water flow for all species.
Strong lighting? I have those 12k lights, is that going to work for these little guys?