[Stones]

Sorry, I should have been a bit clearer. What is typically recommended when a SPS coral is suffering from RTN or in some cases STN is to cut the dead area off of the coral and remount the still-alive piece to a new frag plug or piece of live rock. When cutting off the dead area, it is best to make the cut about 1/4" into the healthy tissue so that you are left with one piece that is completely alive, and another piece that is dead accept for the very bottom 1/4" or so. By making the cut 1/4" into the healthy living tissue, you basically reduce the chance of the coral continuing to STN or RTN.