Hi guys and gals,

I'm having a hard time i.d'ing this stuff. The live rock it's on used to have zoas, still has some, but then I noticed this white clear flowery thing growing on it. So this stuff is starting to take over the rock and I'm hoping they drown out that stoopid Aptasia. I've killed it 4 times and it keeps coming back! LOL It's worse than a zombie! Anyhow, is this stuff that's growing bad? Good? Help please!

Thanks a lot!

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Looks like a tunicate colony to me. If it is, they're completely harmless filter feeders.

Those are colonial tunicates, really cool looking and it means that your tank is doing well They don't hurt corals or anything so no worries there.

+1, those tunicates are awesome hitchhikers. They come in all sorts of colors and sizes.