Definitely don't kill them, they'll likely nuke the tank. And you could get a bunch of money for those guys. Seriously- rainbow BTAs? $50 easy for a good-sized one, most likely. Hell, if you sold all those at $20 each (which I bet you could get people to drive pretty far to pick up), you'd get some decent cash.
Second the recommendation of the powerhead. Anemones don't like that. When they want to move away from something, they inflate their foot, which makes them super easy to peel off by hand. You could also hold some ice cubes (in a ziploc bag) against them to make them start to move away, or cover them with a big shell or something of the sort. I don't think BTAs have much of a sting? Pretty sure you can handle them without any discomfort, and I know they're not dangerous. If they're uncomfortable for you to touch, latex gloves ought to do the trick.
Second the recommendation of the powerhead. Anemones don't like that. When they want to move away from something, they inflate their foot, which makes them super easy to peel off by hand. You could also hold some ice cubes (in a ziploc bag) against them to make them start to move away, or cover them with a big shell or something of the sort. I don't think BTAs have much of a sting? Pretty sure you can handle them without any discomfort, and I know they're not dangerous. If they're uncomfortable for you to touch, latex gloves ought to do the trick.



