white barnacle type specks on aquarium glass and rock

[bscalise]

I have a saltwater aquarium and recently noticed white hard barnacle or snail like specks on glass and rock. they seem to be multiplying. does anyone know what this could be?

 

[Scottm]

a kind of small feather duster worm most likely. they are harmless filter feeders. otherwise could range to hydriods or even barnacles but those are nearly impossible to keep alive in an aquarium.

 

[DragonForce]

Small dusters, signs of good things! I only clean them if they are on the front glass. You can choose to scrape them off or remove them with a magfloat or other magnetic glass cleaner.

 

[Fluff]

They are Spirorbid tubeworms. A type of polychaete and it's completely harmless. They are a sign of a healthy maturing system. As mentioned, they scrape of easily enough if you don't want them.