Please ID!

[bildotang]

I don't know what the heck this thing is. It's kind of waxy looking, and stringy. It's slowly growing, so I'd like to know what it is before it's too late (if it's something wrong). It came in on a new piece of fiji live rock.

 

[nm reef]

Very possibly a sponge...I had a massive growth that looked like that behind the LR in my old 55 display...still have a lot remaining in the refugium. Mine had larger "tubes" in the structure but yours looks close to what I have. Mine was never a problem...not very "eye pleasing" but safe.

 

[cptn howdy]

i got tons of that stuff 2. i always thought it was because of my galaxy coral.

 

[bildotang]

So I should just leave it? Does it serve a purpose?

 

[jb rekit]

I've got 2 also and they have never seemed to do anything bad. Mine don't even really grow.