What the heck is this?

[JerseyJoe]

Hello...Suddenly, I have two of these growing in my tank. They seem to be growing pretty fast. This one is really harshing my Zoa's vibe. Any help would be appreciated. TIA!

JJ

 

[Kasrift]

Aiptasia. Bane of existence.

 

[20gallonreefer000]

Aiptasia, little anemones that spread pretty quickly and can sting corals.

 

[JoJosReef]

Hello...Suddenly, I have two of these growing in my tank. They seem to be growing pretty fast. This one is really harshing my Zoa's vibe. Any help would be appreciated. TIA!

JJ

Kill it quickly. They spread quickly. If that is a frag plug, I would carefully lift it out of the tank and scrape those off completely, rinse in a new container of saltwater (maybe twice), and then glue over the spot where it was.

If you have kalk (or pickling lime), you can make a thick slurry out of it and inject the slurry right onto the face of the Aiptasia. It will kill the aiptasia and the zoas will be fine--might be a bit ticked off, but they are already ticked.
Lemon juice injected directly into the mouth of the Aiptasia also works.

They are very hard to contain, so kill on sight.

 

[landlubber]

further still... manage them. If left alone Aiptasia will grow and multiply until every coral in your tank is stung to death.

 

[Crabs McJones]

Yup, Aiptasia unfortunately

 

[JerseyJoe]

Yikes... Thanks for your help, peeps.