my mom told me a horror story on how she lost her entire, beautiful freshwater tank when our area was hit with an ice storm and we lost power for close to a week. Of course, the filters and heaters stopped working and the fish died. Do any companies make battery powered heaters? This would be a good emergency item to keep around, since the hellhole I live in seems to get these ice storms every few years. We seem to lose power at least once a year around here.