Just noticed that a once healthy frag of zoanthids looks like it is having some issues. All water lvls look good, minus my calcium lvl a little high (havent added anything to it and regardless of water changes cant get it below 600).
SG Nitrates Alk PH Calcium Amonia Nitrites
1.02 5.00 2.50 8.00 620.00 0.00 0.00

Here is a pic from around 2 weeks ago...



Here is a pic of the frag now....



Anyone have any ideas?