Don't worry about it.
If you really have to do something, get an airline with an airstone on one end and put the airstone in a tank. Blow air into the airline to create bubbles. Do this for a couple of minutes in each tank, about once every 30 minutes.
You can buy battery operated air pumps for this if it happens again in the future.
If you have HOB (hang on back) power filters, take a few litres of water from the tank, lift the lid of the HOB filter, and pour the water into the HOB filter. Do this a couple of times an hour during the power failure.
If you have an external canister filter, take the outlet hose out of the aquarium and put it in a bucket next to the filter. Let the bucket fill up with water from the filter. Then put the outlet hose back in the aquarium and pour the bucket of water into the tank. Do this a couple of times an hour during the power failure.