As someone, that has wasted their $ on the wand...I can tell you, that it is basically, USELESS!
Unless the majanos/aptasia are fully exposed, and you spend enough time to 'zap' every living cell, it will be back (some within the hour). I let some friends try it, and they had the same experience.
I ended up getting a bristle tail file fish, and he cleaned my 450g DT, 60g QT and 20g frag tank... in less than 2 weeks...also very easy to catch and remove.