My 42 hex tank has been horribly infected with aiptasia for several months now, and I'd finally gotten the point where I decided to break it down, move the corals and inverts elsewhere temporarily, and bleach everything to start over. Lo and behold, earlier this week I noticed that my aiptasia started a massive shrinking and die-off. I had no idea why but thought maybe it was because I had stopped feeding the tank on a regular basis (there are currently no fish in the tank so I only feed it about once a week or so). Well, I went to feed it two night ago and the water was frigid - turns out my heater died sometime in the past week, and the temp had dropped to about 66F. Corals and inverts (miraculously) were still alive. I've since bumped the temp back up to within normal parameters but the aiptasia is now only a fraction of what it was! At this point I now plan to pull my rock, put it in a tub and let it get down to about 65 for a week or so to kill of the remaining aiptasia hopefully without disrupting the bioload of the rocks. I stumbled on this and wanted to share with others. I've heard of a few other reefers who have successfully kept fish/corals/inverts in a cooler (as low as 62F) tank for a short period time without loss during power outages and such - and while I certainly wouldn't recommend taking a fully stocked tank down so low, I am super impressed with the idea of being able to pull my rocks and put them in a lower temp to kill the aiptasia without (hopefully) killing the full bioload of the rocks. I wanted to share for whatever it is worth!