what is it?

[one24fan]

i got some live rock last week. i've been scrubbing it with a toothbrush
like the directions say. Now i got some kind of cocoon looking growth on it. is this normal? what is it? any help is appreciated.
thanks,
Daniel

[bertoni]

That could be a lot of things. As one wild guess, you could google for some pictures of Sycon or Scypha sponges. Can you post a picture?

[one24fan]

sorry no camera. it looks just like a moth or butterfly cocoon. and seems to be growing. it's white in color. if thats any help

[arc41120]

Sounds like a sponge. What kind of texture does it have? Lots of holes? Is it somewhat transparent? Without a picture you are going to have to be pretty specific on the details.

[cfarrow2]

gotta be a sponge.