Power failures can wreak having on your aquarium livestock, even if they last only a few hours. Oxygen levels will quickly become depleted, killing off fish en masse. Soft corals and most invertebrates are a bit more resilient, but hard corals will also quickly fade as duration of the power outage increases. In the event of a power outage, a generator would be most ideal. However, most aquarium hobbyists do not own one and must use bait bucket bubbles or manually agitate the water’s surface.