Unusual Bubble on Hammer Coral

I've had this hammer coral for about 8 months and it has been growing like crazy, so when these large "bubble" showed up (and I did a little research on hammer coral growth) I wasn't too concerned. But that was 3 months ago. Now I'm worried I've confused new growth for some sort of response to a parasite or being generally unhappy. There are 3 of these "bubbles" (at least quarter size) on the coral itself. Any ideas on what it is? I'm planning on popping it, so I'm just looking for some input.

 

that's odd ..I wouldn't pop it though. jmo
bump

 

abnormal growth? That's weird.

 

I have definitely seen this before but give me a while I will see if I can find the info if no one else chimes in with it first.And I definitely agree with LG don't pop it!!!

 

Definitely do not pop them. What are your parameters?

 

I'm a bit OCD with parameters, so over the last 2 years (since I started the tank and it cycled) they've never strayed from what I would consider "normal":
SG: 1.024-1.025
Ammonia: 0 ppm
Nitrite: 0 ppm
Nitrate: <5ppm
Calcium: 400-430
Phosphate: 0 ppm

 

Magnesium and Alkalinity are important do you test them? I am still looking.

 

Woops! Alk is ~9 dKH, but I don't test for Mag, although I know I probably should. Thanks for the help!

 

Yes definitely!!Magnesium is what keeps the Alk. and Calcium stable.Can't find the actual article I was looking for but from what I remember when they form a bubble they are actually going to start producing some new heads which is great. I am pretty sure it is nothing to worry about and don't pop it.LOL