whaaaaaaaaaat is this ???

[dclegern]

Still grasping at straws ya'll over this white thorny mass growing from under my live rocks.
some say it's a parasite, some a fungus, others say a sponge, etc.
it was cool at first (rapid growth in a slow tank) but once it started choking out some of the wanted. I found as much as I could, and scrubbed it off in a holding tank.

I wish I had a good picture, but look around the edges of the sponge.
almost like a thorny spider web, very white. started near the skimmer.

Aaaaaaaaaaaaaaaaargh!!

[Europhyllia]

Looks like a sponge to me. I have them growing only in between the rocks (where it's dark) and really don't mind them. For me they just sort of cement the live rock into place.

[medi]

I agree. It looks like a sponge. They are beneficial filter feeders.

[justahobby]

What type of lighting do you have?

[dclegern]

t-5 lighting @ 2.5 w/per gallon..............
seems to be random sponges according to the consensus. But I'm still weary of it.
I've stopped messing with the tank, stopped the phyto charge. and I guess I'll wait and see.

[Mr Cob]

Sponge.

[JoshOdphi]

yup white sponge....i have em all over my tank as well....

[justahobby]

It's typical for sponges to grow in low lit areas. It sounds like your lighting isn't especially intense which makes it more plausible for there to be sponge growing on the underside so rapidly.

First pic and also halfway down the page looks exactly like yours:
http://www.wetwebmedia.com/lridfaq9.htm

They call it a Leather Latticework Sponge:
http://www.reefcentral.com/forums/sh....php?t=1777619

Here's a couple variations of the Leather Latticework Sponge (last pic):
http://www.myawesometank.com/wiki/in...brates.Sponges

[SoLiD]

Sponge... very beneficial biological filter.

[Kristy]

Hey.... look who posted! Good to see you around, SoLiD!