Just for your info, I have this great book by Eric Borneman, you may have it also. Anyway, this is what he says about Elegance coral (Catalaphyllia jardinel).
Natural Location: Elegance bury their base in soft substrate, and their hugely inflated polyps and tentacles wave on the bottom, making them all but indistinguishable from an anemone. Like open brain coral, Elegance are often temporarily attached to substrate while young, but break away to become free-living when mature. Elegance are common in lagoonal areas with soft or muddy bottoms (though they may be found in other areas),and in inter-reef areas where they commonly share space with fungiids, seagrasses, and other lagoonal flora and fauna.
Captive care: They prefer a gentle current that does not lift them out of the substrate. Specimens are best placed on soft bottoms, since the dramatic tissue expansion can cause abrasion to the polyp if placed among live rock. Such abrasion can lead to recession or brown jelly infections. These corals can occasionally "bail out" of their skeletons, and may do so in response to poor water parameters or sudden changes in lighting and water quality. This is not a normal form of reproduction, but seems to be an escape reaction. The polyp will fortunately begin to calcify again, if conditions are appropriate. Small buds, similar to those of frog spawn, anchor, etc. are commonly produced in captive specimens with surprising regularity. They seem to possess a willingness to "swap" zooanthellae in response to changed lighting, leading to the presumption of maladjustment, disease, or impending death. Remaining contracted, sometimes for months, they may suddenly "snap out of it" and again expand normally with subtle to dramatic color differences. They are sensitive to the presence of many soft corals, and may even be adversely affected by Caulerpa algae. They succumb to infection easily, are prone to bristleworm irritation, can be easily punctured or torn when inflated, may recede in aquariums with significant filamentous algae growth, and may require dietary supplementation to maintain long-term health. In short, they are quite frequently problematic. Many years ago Elegance were among the easiest corals to maintain, but the majority today are not surviving. They adopt an abnormal appearance, with an initially swollen polyp body and shriveled tentacles. Eventually, the polyp shrinks tight against the skeleton and succumbs by recession or opportunistic invasion. No environmental or treatment protocol seems to help.