[Chin_Lee]

Mr. Salmon King,
I've read two threads (well one started off as power outage killing ick) regarding garlic use. Many people have posted their personal experiences on the use of garlic which worked for them. Please just take their word for it that it did work for them. As to why garlic is not used on fish farms or what not, that is a separate issue and should be asked to the Department of Fisheries and Oceans who (i believe) oversees the fish farms' procedures.
An individual posted medicinal properties of garlic that may contribute to the success observed by different aquarists. But I don't believe anybody have observed ick cysts or parasite falling off their fish and seeing these parasites writhing on the floor of their aquarium and subsequently dying after using garlic. Most people have just observed that their previously icky fish were no longer icky after they used some sort of garlic intervention.
If a power outage can get rid of ick, then (as previously mentioned by Howdy) we would never see any ick on our fish after a 16-30 hour ride in a plastic bag without power. Your experience on getting rid of ick your angel is incredible and further details may provide an insight on how it occurred.
What other livestock did you have in your tank?
Which corals died off?
I am not suggesting anything but maybe one of the corals that died released something into the water that caused the ick to disappear which is something that you should look into further.
I have no doubt that your angels are ick free and what you experienced was something great. However I don't believe that losing power is the direct cause of it. I also have no doubt that garlic has also worked for many people as it had also worked for me in the past.