Like Linckia, indications are that it is an algal/bacterial film grazer...but there are also some indications that it might actually feed on encrusting stuff like certain encrusting sponges,bryozoans, etc. It is not a large species if I recall, but the real indication is survival beyond a year. The can take an astonishingly long time to starve. Oddly enough, I am not necessarily telling you to definitely not get one. But I will tell you that there is no guarantee...they are definitely not an easy star...I've seen many melting at various LFSs. For a star in your size tank, IMO, a Linckia multiflora is the better bet.