Hey everyone wondering if anyone has some experience with this zoa problem of mine. As of Saturday last week I noticed my Aspen zoas started to bulge in the middle and the frills were withered. Within 24hours all the polyps of the zoa colony withered away. Next went a small colony of armor of gods near the apens. The same symptoms of bulging center with withered frills. One day later it affected 4 other zoa colonies with the same results. I immediately decided to do a water change of 30% to see if it would alter the course of the mystery problem. I checked my water quality and the results were as follows: pH: 8.2, Ammonia: 0.0, Nitrate: 0.0, Nitrites 0.0, Phosphate: 0.05, Spec Grav 1.026, Mg 1290. As you can see I don't think it is my water quality. Recently, I added three large acro colonies to my system on the same day the zoa problem began. One of the acro colonies died just a week later due to ,what I am presuming, the fact it was wild caught and did not acclimate to captivity. The other two are doing fine. Another change that occured 5 days earlier is that I began dosing Mg in my tank. I am using B Ionic Mg by ESV in the approriate dosing according the the instructions. My starting Mg level was 1100 ppm before dosing. I am at a loss of both wonderful corals and my mind. I would appreciate any help.