What is this? White tube? Pineapple sponge?

[M3rmaids]

In my 100 G reef tank, I have a few of these white tubes, predominantly on frags.

Are these pineapple sponges?
Please help me identify, are they harmful?

 

[ISpeakForTheSeas]

Those look like pineapple sponges to me (though it’s a bit odd seeing them on frags). They should be totally harmless, so unless they start smothering your frags, I wouldn’t be too concerned.

 

[EricR]

Yes... definitely pineapple sponges.
They love one patch of zoas in my tank for some reason.
I've plucked, H2O2'ed, everything -- they keep coming back,,, and now there's a firmer sponge matt going on that I can't get rid of.

Good luck ... but definitely pull them off the frag

 

[M3rmaids]

Besides plucking them off. Do they show up due to chemistry? I’m currently raising my alk slowly. Just curious if they showed up from lower alk or where they came from

thank you so much for confirming.
I will start removing by hand!!! Anything eat them? Or keep them back?

Ill start googling now I know they are in fact pineapple sponges!

 

[TokenReefer]

After reading this (extremely long but informative) thread (as well as other information), I want more (cryptic) sponges! They seem to be only beneficial absorbing DOC's etc, excellent filters!

Algea from Florida in a reef

My dad just got back from florida with around 5-6 lbs of Gracilia Marco algea. If I quarantine this stuff and only use a small piece is it ok to use in my reef tanks and to pass along to friends? I’ve never taken anything from the ocean before.

www.reef2reef.com

 

[ISpeakForTheSeas]

Besides plucking them off. Do they show up due to chemistry? I’m currently raising my alk slowly. Just curious if they showed up from lower alk or where they came from

thank you so much for confirming.
I will start removing by hand!!! Anything eat them? Or keep them back?

Ill start googling now I know they are in fact pineapple sponges!

They are probably related to tank chemistry, but I’m not sure how. People say they’re limited by silica, but they are calcium carbonate based sponges (genus Sycon), so I don’t know why silica would limit them. That said, they’re very common in young tanks, and they usually go away on their own after a while.

Long story short, you probably won’t find something that eats them (and if you don’t, it’s almost guaranteed to be something that’s not reef safe). Again, they usually go away on their own, and they’re harmless filter feeders.