Acan in the danger zone

[boleybuster]

I've had this white stuff (looks sort of like sponge) however, it engulfs my heads and is killing them.

First of all, what is it? Second of all, how do i get rid of it?

 

[rssjsb]

It does look like a sponge. I think you just have to try to manually remove it.

 

[Michigan Mike]

What's your lighting like? I have a lot of sponge in a poorly lit tank.