Power Failure Tolerant Air for Aquaponics Fish

I run two high capacity air pumps for my aquaponics fish tanks and grow beds (some of my beds I pump air into).  These are 110v air pumps.  They will run off a large car battery and inverter for about 36 hours.

To make the system tolerant of power failures I do the following:

1. Power a battery trickle charger from mains 110v -- this can supply the 60-90W required for the air pumps.
2. connect the battery to a 150W inverter
3. power the air pumps from the inverter

Now the battery is maintained at full charge while my mains power is on (99%+ of the time).  Should I have a power failure for a storm or other reason, the battery would still power the air pumps for more than a day. My water starts getting messed up if the water pump doesn't run for a day, so this is about the time I would have to take other steps.