What is this?

[demotaz7]

Just noticed these purple bubles on my rock....any ideas?

 

[Sniperhank]

Looks like bubble algae to me.

 

[melosu58]

To me it looks like some closed up zoas. Something seems to have irritated them.

 

[hubbcass08]

Just noticed these purple bubles on my rock....any ideas?

Looks like bubble algae. If it is you need to be careful removing and make sure you do so quickly because it spreads like wildfire

 

[Dallascowboys16]

Looks like bubble algae. If it is you need to be careful removing and make sure you do so quickly because it spreads like wildfire

Yep. If you pop the bubble, thousands of spores get spread around the tank and the problem gets a lot bigger. Really carefully remove them from the rocks being sure not to pop them.