What is it?

[Peteb3]

I need some help identifying this stuff. I had brushed most of it off when I moved the tank last but this stuff just keeps on growing. It hasn't killed anything but I'm scared it might be dangerous. Does anyone know what it is?

Pic is kinda crappy but it is the stringy and oozey mass that I'm talking about.

 

[KathyC]

It's a sponge, good for your tank, a filter feeder. I'd be surprised if it overgrew tour corals. It is usually found on the underside of rock (out of direct light, but some types do grow in light)

 

[Peteb3]

Thanks KathyC, I thought it might be a sponge but then when it started growin the arms I was not sure.