The higher the tank temp gets, the less oxygen there is in the water.
I dont know what size tank you have ( you dont post it ).
I always have a air pump & air stone in my tanks. I also have a battery backup air supply.
It works off of batteries, but you plug it into the electricity. As soon as the power goes out, the battery aip pump kicks in.
I can also go into the APC battery backups. The kind that you use for a computer.
I run everything through the APC battery backup units. If the power goes out. they will keep the pumps running for about 4 hours.
Since I own my own business I have 6 generators, I always have one at home. If we have a power outage, my wife or I can just fire one up. It will also keep the refrigerator..Freezer & lights working.
A small $300.00 generator is a very small investment to save your tank.