I have a Big Strong Generator now, but it messes up electronics badly, So I have to put a small computer ups on every tank to prevent problems with my led lights also heaters. And that also means networking gear, computers and TV's...
These run a long time... That gives me a lot of time to just think that I might have to think to start the generator. And my network is on line all the time.
Once started. It last's weeks on a gas tank. I can run almost all appliances... Heat the house. With the last test it should hold all tanks too...
But I had 5 aquariums in the depth of of the 1998 ice crisis in Quebec and with adequate insulation and forcing water movement in the filters. All made it trough except the plants.