ID Please : Sponge or Fungus?

[HanoverFist]

Recently a white/grayish blob began growing quickly on a piece of LR. There is a sponge growing next to it and it seems totally different in structure. It isn't a thread-like tangled mass, it's more of a smooth blob with grayish jelly inside.

Wondering if it's something I should scrape off before it gets too far.


Bright green baby sponge next to The Blob:

Better pic of The Blob (note amphipod crawling on it for scale):

 

[Allmost]

both are sponges grows in dark areas based on available food. web sponge I think its called, not sure.

 

[kjenkins]

Yep, sponge and I would consider it good and the sign of a healthy tank.

 

[HanoverFist]

Awesome, thanks. It's on a rock with corals and didn't want a fungus overgrowing them.

Wish the green one would grow as fast. Great color to it.

 

[victorcan]

Ive got it almost overtaking my pink polyps?? have like a decent 3" colony and that sponge has woven a web arouind each and every polyp on the colony?? Funny if its called web sponge because everything looks cought in its web
lol i donno just was makin me nervous as my polyps have seemed cut off from reproducing as this web has it blocked around now the lights are off right now or Id take a pic maybe tommorow. Was considering trying to get rid of it??

 

[tunicateperson]

It looks like a sponge to me.