Joe:
With an air pump you're home free... I don't have air pumps so opted for extra batteries to run entire system instead of buying an air pump... Cost of Batteries was a little less for 8 hrs...after that I'm at Hm D to buy a generator...
Just talked to Guy and he's at Halawa Hts at a cutomers house trying to keep the koi alive during a power outage there... I guess he's going to sell another back up system before that's over...
Aloha! Mike