Using off the shelf additives can be good, but why not try a natural predator first?
Pepermint shrimp will eat that sucker up!
Chemicals should be used as last resort most of the time
What kind of rock?? Tenticles are a little short looking. Could it be a hidden cup coral? I have read that they are common hitchhikers on Florida rock.
i have 2 peppermint shrimps that seems to be doing it's job in my 60 gal. i may need to get a another one since I have about 80 lbs of LR. Somebody suggested the Joes Juice to me but also told me to try the peppermints first before I use any chemicals. Good advise!