What’s my bubble coral doing?

[hexcolor reef]

Seen these fibers on the side of my bubble coral skeleton for a few days now and it’s growing and branching out each day.
today it’s doing this bloated thing after I removed an anemone from the tank.

can anyone confirm if this is how coral start to grow its skeleton and should I start adding more calcium?
I’ve been going heavy with feeding reef roids and liking the growth

 

[KrisReef]

This is not how they grow a new branch. I think that branch is a hydroid perhaps?