What is this on my Xenia?

[ckmn101]

Has anyone ever seen this happen before? I don’t know if this is a disease or a problem but I don’t think it is what a Xenia is supposed to do. It is splitting all the way up the base and this green stuff that looks like grass is coming out of it. The green stuff is now almost 1 inch long. When I first got the Xenia (3 months ago) there was a very small patch of this stuff coming out of the side of it and now the grass-like stuff has grown to being almost an inch long and the split is about 2 inches up the stalk by over 1 inch wide (split open I mean). I’ll include a pic and all my tank parameters. Otherwise the coral seems like it is doing just fine.
Ammonia/Nitrite 0
Nitrate 0
pH 8.0
Alk 4 meq/l
Salinity 1.025
Ca ranges between 400-425
Thanks in advance

 

[tecwzrd]

Looks like a type of macro algae like Chlorodesmis fastigiata or Chlorodesmis sp. If so neither grows very quickly.

Can you remove it easily?

 

[ckmn101]

No. it isn’t growing on it, it is split open and growing out of it. And also, man, this Xenia has spread to like 5 places throughout my tank.

 

[tecwzrd]

Not sure what it is then. Doesn't seem to fit the usual Xenia disease issues.