Looks like a Rhodactis sp. (hairy mushroom disc coral) to me. A member of the Coralimorphian genus and will probably do better under moderate lighting. So, if you have metal halides you may have to ensure that they aren't directly in the light (e.g. under an overhang), but if you have fluorescents (e.g. T5s) they can be in more direct light (unless they are the super-powerful T5s like the ATI Powermodules which have MH grade brightness). They'll even grow under normal output fluorescents.
Yes, you might want to compare yours with photos on the internet to see which Rhodactis species you have (by looking at size, shape of bumps on the disc etc). AFAIK, some can be fish eaters and some are safe.