Sea squirt?

[GoodKat]

These things are growing all over the filter chambers of my nano tank. It has been set up almost a year and these things are fairly new.

They look like tiny orb sponges with tiny crowns.

Ignore the only things in the photos. They are white sponges and hydriods.

Thanks all!

 

[TheEngineer]

Pineapple sponge. A filter feeder that most of us find, like you did, in overflows and in sumps. They're good to have around.

 

[GoodKat]

Thanks, I'm suprised pineapple sponge didn't come up in my Googling.

Another successful ID from the community. Thank you Engineer!

 

[Cnidoblast]

Sycon is the genus name for these guys if you want to go on a Google adventure!