If you can pull the frag out you can kill it with fire! If not you can boil up some lemon juice and then inject it directly into the nems mouth. Personally I have never had any luck with lemon juice, joes juice, or aptasia x. I have had luck with peppermint shrimp, only the ones with a dark tail though, and file fish will make quick work of an aptasia outbreak. File fish will eat all of your coral polyps as well though
Sent from the Death Star