Has anybody experienced this or know what it is?

[sawlty dog]

I've had this come up for a little while. I've never experienced it before...has anybody else? Any ideas how to get rid of it? I manually remove it all but it grows back within two to three weeks.

http://s1280.photobucket.com/user/sdalpizar/media/Nuvo%2016%20Tank/20150406_121149_zpskb5jhaib.jpg.html?filters[user]=135365446&filters[recent]=1&sort=1&o=1

 

[gemini aquarius(t)]

Its sponge. And it is NOT good! I had it in my nano, and it ruined it. The only thing i have found that helps are the spiny red starfish.

 

[sawlty dog]

how'd you end up getting rid of it?

 

[tonyyloww]

I have some on the inside of my overflow. never saw it in my DT.