I get power outages many times in my area. what works for me is each aquarium has a sponge filter somewhere in the tank and when the outage occurs, I hook up a battery powered air pump to the sponge filter and I've never lost a fish because of this.
That's intense. Which tri-fuel generator do you use?
What about airstones with neodymium magnets epoxied to one side attached to a magnetic bar - which is an electromagnet: it's a coil of wire around an iron rod and the magnetic force can be turned on by applying current through the coil, and off. When the power's on, the magnetic bar holds all the airstones above every tank because it's attached to the power bar and a few hundred milliamps are energizing the magnet (NC). When/if the power goes off, the bar get's denergized, and drop the magnet which drops the stone into the tank. At the exact same time, an NO solenoid valve attached to a line to a 50 gallon tank of liquid oxygen and the valve opens. Pure O2 passes through the airlines at a rate so the 50 gal tank is depleted in two weeks, and into the airstones. The airstones could also be the same stones used inside custom sponge filter, and a check -Y-valve flips over to let the O2 in if pressure from the air compressor ever stops.
I guess I started that as a question? I heard of something like this somewhere.