What are these?

[Double J]

Cleaning out the skimmer, and its full of these. They are attached to the surfaces, are squishy but don't move.

 

[Coastie Reefer]

Sponges?

 

[truperc]

Tunicates. They are a good thing. Nothing to worry about.

 

[Double J]

Is it possible to put them back in the tank? They really brought down the skimmers performance

 

[erinmegan85]

Look like pineapple sponges to me! Good filter feeders, but if they're bringing down you skimmer performance best to get them out of there.

 

[Double J]

Had to clean them out, but did notice a few still in the tank.