My pulsing Xenia rapidly increased in numbers at the top of my tank on this one rock. I wasn't really paying attention because I forgot that softies can release toxins. Then I see that the purple Monti Cap that was right next to the edge of that rock has a white spot about the size of a quarter on it's left edge. I didn't know what happened. In 1-2 weeks, the white spot spread over the whole piece and now it's mostly dead. After that, I went on a mission to remove the Xenia from elsewhere in the tank in the little spots where it has sprung up and also to remove a fair amount of it from that rock at the top of the tank. I'll see if I can get a picture tomorrow.