sorry to hear it!! I had a fungus thing that started at the base of the tail and worked its way down exposing the spike and seemed to eat away the body of the tail. I could get no responce from treatment and the other 3 rays were fine. Unexplained anoying death!!
May i subjest a RO filter. It will get rid of all of the ammonia, nitrite and other polutants that bother your ray. It cost around 150 bucks. i bought one still awaiting to instal because of my plumbings all screwwed up...