IF it is a Sclero, then it is a nonphotosynthetic soft coral. Light is irrelavent- strong water flow and heavy feeding will be needed. Many people say that Sclero feeds primarily on Phytoplankton, so get yourself a good stock of live phyto, and dose daily (or preferably a slow, constant drip of it into your tank).
IF it is Lemnalia, it is photosynthetic- moderate light, moderately strong water flow. May still benefit from feeding (whether it would take phyto or zooplankton though, not sure. Im betting more like zoo-sized stuff. Rotifers, small copepods, Marine Snow, etc.
Im still betting on Sclero though. Hopefully someone else will chime in to second me though.