What the heck is this?

[seattlereef]

Was just relaxing looking in the tank when I saw this

 

[seattlereef]

On the right is a sponge. But not sure what's on the left side.

 

[1guydude]

well im gonna say dried up or dead hydroids. Maybe a worm tube or something. I see a lot of HA though, u should get a seahare or something and stop the source of that. Just my .02