Pulsing Xenia Problem

[skimmer]

I have a ton of Pulsing Xenia in my tank but for some reason it looks like some of the tips are being eaten off. I do not have anything that would eat them. Some of the arms have the tips missing and some have the whole arm shrunk down to nothing and look like little white tips.
Has anyone had this problem?
Water parameters a OK.

 

[flydan]

Hey,
Before you say you have nothing that would eat them, why don't you list what's in your tank? You might be suprised at what you find out. Some critters that are advertised as "reef safe" are not, especially when they get bigger.

 

[burnnspy]

What are the water parameters?
BurnNSpy