Xenia not lookin good

[Edmonton Eskimo]

Xenia is a funny coral. I had some that was growing like crazy and splitting and all was well. All of the sudden it started to die one day and now I have none. I have heard that things like this happen with xenia. I know that they are sensitive to changes in water chemistry but I couldn't find any changes in my water when I tested it after the xenia started to die. Puzzling