Requires clean water and zooplankton (e.g. brine shrimp) to maintain. As already mentioned by everyone -- not an easy to keep specie.
if the specie starts to degrade, you will see white sections appearing on the branches, it means dead spots, after a while if algae takes over the dead spot it means the beginning of the downward spiral, it may take a long time or short time to degrade but once the coral starts to degrade it's an almost guaranteed death.
so prevention seems to be the only way --> going back to maintaining those 2 conditions: clean water (low nutrient level) and food availability.
one health indication to look at is the appearance on the branch tips of those "transparent needles", quite difficult to notice unless you look carefully. my experience is that as long as those "needles" are around the coral is still doing well.
one last point, as a non-photosynthetic coral, it does not appreciate light, in fact, imo, exposure to light may likely have an effect on the animal's health
I have noticed one reefkeeper buying this type of coral in a large quantity, i do not know how he/she does it, but i was told by the importer that it was possible for this particular reefkeeper. Perhaps that reefkeeper's captive environment was a non-sps set up i.e. non-photosynthetic corals e.g. Cauliflowers, Seafans, Sunflowers in a dimly lit tank, well fed, highly skimmed . I'm making a guess here ...