Good or bad?

[Mark Bradley]

A number of them in my sump. To me they look like a miniature Sea Hare - not sure if they breed and I’ve not had an adult in the tank for over 8 months. Can’t get a better photo so hope it is obvious to those in the know what it is?

 

[dwest]

I would guess pineapple sponge if they are not moving.

 

[Mark Bradley]

They seem to like hanging on the sides of the sump but I did find one in my filter sock so assume they do move

 

[NashobaTek]

+1 pineapple sponges

 

[dhanking]

+1