I don’t know much about this BUT living in Fl I get my fair share of power outages. For short term outages. What in my opinion is paramount in an outage is gas exchange and water movement. The majority of gas exchange accrues at the surface. In an outage use the container method. Take any type of clean cup, pitcher or other container, scoop out and fill it with aquarium water.
Hold the filled container some distance above the aquarium, and pour the water back into the tank. Repeat this process numerous times. The water splashing back into the tank will generate oxygen in the water. You can buy a battery driven air pump and put an air stone in the tank. As for water movement . a battery operated hand blender will do or even just use your hand to move the water around periodically