Good or bad?

I have two "things" that grew in the last few weeks that I can not identify. One is a bunch of something that looks like polyps. (could not get the camera to focus better) They are very small, less than 1/8". The other "thing" is the white bag with a tube sittin in the rock crevice.
Thank you for your help.

 

The first image looks like colonial hydroids, they are bad. Really need a better image to be sure.


The white tube thing in depression is a sponge harmless.

 

I Second That.........

 

ditto

 

The first photo does look like hydroids to me. Kill them!! They are worse than aptasia IMO. The second looks like some kind of sponge to me. I have a few similar looking ones, a few white ones and a pink one.

 

Thank you all for the prompt reply.
Not good news about the colonial hydroids. Apparently they are tough to kill. May have to take the rock out yo kill them off.

 

If the colony is small and isolated you can take a pieces of epoxy and cover them completely for a week or so and then remove the epoxy.