Not sure what I'm looking at.

[MarkSativa]

My tank is only a few months old. I received some chaeto from a local reef club member recently and added it to my tank. Since then I've had some issues. First my fish all got ick and my powder blue and 2 clowns have passed on. I still have a foxface and a wrasse left. I've noticed 2 or 3 aptashas. Killed them and that's done and over as far as I can tell. Then this morning I get into my sump and the glass is covered with these little larvas. So what is it? Good or bad? There are thousands of them. I had a reef for almost 10 years before and never saw this.

 

[DancingShark]

Pineapple sponges

 

[Lovemyreef2015]

To me they look like a bunch of little sponges.

 

[DSC reef]

There good filter feeders. There numbers diminish overtime but nothing to be concerned with. I like sponge in the tank.