Ihave had a bubble coral for about 3 weeks. for the last week or so the tissue that covers the rock and stony part seems to be dieing and sluffing off. It does not open up as much as it did and sometimes it appears to shudder and excrete a brownish slime. My tank is 55 gal. NO3-0, Calcium 400, PH 8.4, alk 3.2, phosphate 0. It ther a dip or somthing I could try to medicate it with incase it is a bacteria or something?