Bubble algae or something else?

[I<3Reefer]

Any idea what this is? Mostly on the front of my rock and on the side of my power head... are these just air bubbles or is it the first stages of bubble algae? They seem well connected to the surfaces they’re on...

 

[I<3Reefer]

 

[I<3Reefer]

 

[I<3Reefer]

Also there’s one of those bubbles just hovering above a coral polyp seemingly connected to nothing...

 

[I<3Reefer]

Was trying to think, this tank has not had any addition to it in 2 months (skunk shrimp) and then a month prior to that. But yesterday I switched out the carbon... could these bubbles be from that?

 

[Gareth elliott]

Do they pop? They look rather translucent for bubble algae. If its algae looks more like o2 or co2 that was trapped in a layer of algae, like you get with cyanobacteria.