Aptasia X works great. Squirt the stuff right into the little disk without touching it...do it quick, because they spread like fire. Boiling water is a joke, and lemon juice does nothing. By the time the water boils, you draw it into a syringe, to get into the tank, and reach the critter, it's too cooled off to do any damage. I have also tried the lemon juice and it didn't hurt it at all. Joes juice can be hard to find.