Looks like aiptasia - positive id would help.

I don't know the policies about putting product names on the site, but being in Calgary there is a product out of BC called Tailored Aquatics Aptaisia Destroyer or something along those lines. It's from Tailored Aquatics and worked well on my friends tank. You can find it at J&L Aquatics website.

 

Technically it opens up a wormhole in the fabric of space/time and the anemone is sucked into the abyss. On the outside, it looks like it's eating it then shrivling up and dying...but...abyss. yes.

 

I've had great luck with peppermint shrimp and Joe's Juice. The Juice kills the big ones that the shrimp won't eat. The only thing with the shrimp is that their fatality rate upon introduction (even drip method etc.) has been about 50% for me, and they only live about a year. Also, mine have liked to crawl deep into inaccessible rocks and die; and if you have an underpowered protein skimmer like me, this can lead to problems.

 

We bought 3 pep shrimp once. 1 died during shipping. 1 was dying upon introduction, then crawled into the rocks and died. The last one was around for about a week, we bought a pistol shrimp, and he has gone MIA never seen again. Joe's Juice for me!

 

Thanks for the info. I ran down to the LFS and grabbed some Joe's Juice. Worked like a hot damn.