Is this sponge?

[markbauernfeind]

This stuff is starting to show up everywhere in my 55 gal reef. I think it arrived on a ricordia rock I put in about a year ago. It is easy to remove when it gets too large, or blocks the return. Don't have much experience with posting to this site or attaching images, so pix may not show up. Any info or insight would be appreciated.

Just noticed Preview Post option, looks like I did the image import correctly. Looking forward to advice from you experts out there!

 

[SDguy]

Looks like red bubble algae to me.

 

[Sugar Magnolia]

I agree. It's not a sponge. It's some sort of algae. Browse through here - http://www.saltcorner.com/AquariumLibrary/browsesection.php