Web-Like substance on LR?

I noticed this weird substance on one of my LR tonight. Never seen it before, but it's like some type of webbing on the LR. I noticed a lot of small star fish nearby, some perhaps something to do with them? Any help would be appreciated!

 

Sponge?

 

Are any Sponges clear like that? I haven't added anything new to my tank since January so it would be a neat surprise if so. Thanks!

 

I had a sponge that looked similar to that. Get rid of it asap. Scrub it off with a tooth brush or point some flow at it. It hates flow. It will get bigger and like smother green star polyps, zoanthids, etc. If its the same thing, it will end up looking like this:
(It looks more clear than white in person, that pic was on my cell phone)


And if you look really close you will see, or eventually see a few of these things (don't mind the quick sketch):

 

I had the exact same thing, it was the same color too. I found out that it is actually a collection of bacteria. I ended up throwing the whole piece of rock out because even when I thought i got it all off it would just grow back. I ended up throwing that rock out just to be safe. I suggest the same. Or Take a hammer and chistle and break off that part of the rock. Better safe than sorry.

 

Good to know, K+! I'll try scrubbing it off first, then breaking it off. It has sort of grown over the last month, but not very fast.

 

its clear sponge mostly everyone says its harmless