What is this. Good or bad??

[bkushy]

If its bad I want to catch it while I can see it. Thanks for any replies.

 

[Bill0181]

Asternia Starfish could be back if its eating your coralline algae. It's a toss up, some say they are fine and some say get rid of them. I would just say watch them, they multiple quickly.

 

[AbsoluteFaye]

That looks like a stomatella snail. They are a good part of your CUC. Leave him be. I have a bunch.

 

[carey]

Yep. stomatella. Harmless. i agree, just leave him be