The method being reffered to for getting rid of the aptasia is simple, mix up a few teaspoons of pickling lime with just enough water to make it into a thick paste, apply the paste right to the aptasia. Smother the suckers with the paste, we use a syringe (minus the needle) they'll be history within 24 hours. The paste will disolve into the water column as calcium that is useful for other inhabitants.

Just be as careful as you can not to paste up anything you don't want dead and gone, it's quite potent.