I've had an Orca marine tank setup for about 2 months and have recently seen these. I think they are barnacles but are definitely not sure (They seem too "fleshy" to be a barnacle to me)! Any suggestions? If it is a barnacle, I assume this is a good thing?!
Sea squirts? I have them in my tank and that's what I got told they were by the knowledgeable ones on here. I googled for photos and found several that matched. I have them in green and reds too in my tank. Some are quite long and others are in clusters.