What is growing on the bio-blocks in the refugium?

[MinnesotaReefer]

 

[DeniableArc]

I’m guessing some kind of spaghetti worm, someone here will know.

 

[Goaway]

I’m guessing some kind of spaghetti worm, someone here will know.

Half right, white spaghetti sponge.
There's mixed opinions on keeping any sponge. Some have said they produce toxins that reduce coral growth rate. I personally keep my sponges. Up to you.

 

[MinnesotaReefer]

Half right, white spaghetti sponge.
There's mixed opinions on keeping any sponge. Some have said they produce toxins that reduce coral growth rate. I personally keep my sponges. Up to you.

Excellent, thanks much!

 

[captain_jimmy]

I have the same stuff in my sump.

They spread like crazy. I pull them out regularly but leave the bits that's get broken off and they just propogate again.