ID Help please.

[CristinaNTimothy]

Hello everyone, my son has a fairly new setup that we bought second hand with rock that we transferred over from his smaller setup, I put it through a vigorous cleaning and allowing it to dry out well I guess I should have bleached it…. Either way that’s another thread topic, but now there are things popping up all of a sudden which I need help with identifying please.

Some were growing on the sand that I took out and are in the net.
I don’t think this is aptasia as it doesn’t retract at all when touched or manhandled.

Pics are attached


Help would be appreciated.

 

[Troylee]

Sponge.. it’s harmless

 

[CristinaNTimothy]

Sponge.. it’s harmless

You’re awesome… thank you for your quick response I appreciate it.

 

[BryanM]

I have a fair amount of those in my system as well.