what is this

[brentjennifer]

Hi we are just starting up a 55 gallon tank this is on one of the live rocks anyone know what It is?

[CafeReef]

Looks like a spounge or maybe reef putty. Lean more spounge, to smooth

[brentjennifer]

It was on the live rock when we bought it we just weren't sure. Thank you

[theMatrix]

Are you talking about the white worm?

Thats a tube worm...
Usually when asking more in detail of what your describing in the photo would help.

"This white worm looking thing on the rock we purchased" or "this white thing in the middle kind of between the rocks"
Theres two things in the photo that im questioning.
The best way of asking...would be using your phone and circling what your asking about?

Red...or green.

http://i.imgur.com/HqQF2QI.jpg

[brentjennifer]

Green

[brentjennifer]

...

[Quiet_Ivy]

Agreed with above posters, some kind of sponge. Totally normal, harmless and will probably go away on its own.

hth
ivy

[BillNye]

You're fine.

[900801]

The one in red looks like vermetid snails.