Spider Web looking thing

[NicksTanks223]

I found this spider web looking thing in my tank in this one corner of a rock. I just need help to ID this in case it is bad or something I should treat. Thanks!

 

[Spare time]

I am thinking a sponge but its a little dark to say for sure. They are great for the tank though and act as little filters.

 

[html]

For me it is some kind of sponge

 

[NicksTanks223]

I am thinking a sponge but its a little dark to say for sure. They are great for the tank though and act as little filters.

Here is a better picture. Would the sponges jsut be in the rock and then start to grow over time?

 

[Spare time]

Here is a better picture. Would the sponges jsut be in the rock and then start to grow over time?

Yup thats a sponge!. They grow over time, especially if you feed foods designed for filter feeders.

 

[NicksTanks223]

Yup thats a sponge!. They grow over time, especially if you feed foods designed for filter feeders.

Yeah I just started feeding like 2 weeks ago and I guess that made it grow pretty quick.