What is this going in my sump ?

[reefah]

***growing***

Should I remove it or leave it?

 

[Dburr1014]

Don't know what it is, some kind of nudibranch or slug. Isolate until you can get a confirmation what it is. Could be good or bad.

 

[reefah]

Don't know what it is, some kind of nudibranch or slug. Isolate until you can get a confirmation what it is. Could be good or bad.

Will do thank you!

 

[Sharkbait19]

Does it move or stay stationary?
Might just be a pineapple sponge, if so, harmless.

 

[ying yang]

If doesnt move which I take it that it doesn't as you didnt say it moved,just that it's growing.
I would guess its some kind of sponge ,especially if sump is dark as most sponges like/ prefer nice shady/ dark spots.

If it moves could be numerous things ,looks like some certain spiky cucumbers ,like a baby version but i don't really know tbh ^_^