I.D. needed on growth in tank

I found this sort of fungus or mold looking thing growing on one of my rocks. Any ideas? I know the pic isn't the greatest.

 

I really can't tell. I don't see what appears to be a mouth or spout. Maybe a sponge.

 

ya Looks like a sponge. It's a good thing and a good sign your tank is doing well. Some critters eat sponges or if it remains it will be a good filter feeder.

 

Jason,

What about what some people call ' reef snot '? Don't know it by any other name

John

 

I'll try another pic.

 

John,
Can't say I've ever heard of Reef snot (feeling like I'm walking into something) But could they both be sponges of some sort



Do you have a pic of this "Reef Snot"

J

 

I remember now, I was thinking of snot algae or dinoflagellates

John

 

Still looks spongy to me!

 

As Craig said, it looks like a sponge.

 

Is this something to worry about or is it a good thing to have in my tank?