Aiptasia anemone?

Great info guys. Thank you so much.
Looks like I might have done the wrong thing so I'll keep everyone posted on progress.
The post above about most live rock has them is funny. But wouldn't that mean the entire(3 large wells) are infected with this? If so how do you even start to get rid of them.
You guys are the best.

PS I did not boil the entire rock. I laid upright and dumps boiling water on the spot. Which was on the end knob. It was fat too. Couldn't get back inside the rock. I think it exploded because it was just gone.

Again thanks. I'm learning everyday. But your knowledge it would still in the tank

 

You're still alive, so no harm no foul. However, boiling rock will kill the beneficial bacteria on/in it, making it dead rock rather than live. If you have more live rock in your tank that hasn't been touched, it should be fine, as that dead rock will regain the bacteria over time.

For us, peppermint shrimp and Joe's juice did the trick with aiptasia. All rock from an LFS will have some unwanted hitchhikers on and in it, it's just one of the many pains of setting up a tank. Once you have an established tank, where any LR hitchhikers have met their demise and your rock is clean and doing it's thing, you really shouldn't add any more LR to avoid having to go through all of that again. Any rock that gets added to our tank now is 100% dead.

 

The only method that worked for me every time a head pops up was using Aisptasia-X from Red Sea. As long as you move slow and gentle with the syringe and trick the thing into eating the stuff, you can literally watch it swallow that stuff and implode. Does the trick for me everytime and you don't have to deal with the boiling water and other more involved methods. Took me about 15 min to erradicate my whole tanks problem when I had it the first time. Haven't had a problem since.

 

I use a plumbers butane gas flame torch it cost £12 at B & Q, I pull the rock out fire up the torch and Zap the pest for a few seconds, They are gone for good and its minimal die off for the bacteria on the rock.

 

Boiling live rock will make it dead rock, also as some have said it can make you pretty sick if you breath the vapors. If you do boil live rock please do it outside and stand up wind. Some of the stuff in that rock can be pretty bad for you.

cool fact: Pacific island natives dipped their spears and arrows in palytoxin to make sure their enemies died!
Wear gloves haha
good luck!

Anyone seen the guy burning them with the blue laser on youtube?