I have two battery powered air pumps for the fish, since that seems to be the only thing that they really need. In the past, I lost a dottyback and a clown because of low O2 during a power outage. I have a UPS, but it only lasts 5 minutes with the heater, so I gave that up. I kept the tank reasonably warm (72) by throwing towels over the tank and putting on my gas fireplace. Fortunately, I just got back power two hours ago, and so far the only casualties I can find is my Xenia colony and one of my feather dusters, which dropped its head but I'm hoping it will recover.