Valonia of my GSP frag?

[synapticfire]

I am pretty new to this. I have a green star polyp frag that has not been thriving.
it was one if 5 frags I got from WWC, and one of my first. About 2 months old.
I was inspecting it today and found this?
What is the best way to deal with bubble algae before it becomes a problem?

 

[crazyfishmom]

Physically remove it. If you can, take a cotton swab with hydrogen peroxide and gently scrub the area after you’ve removed the bubble.