Having a disaster recovery plan in place before a disaster happens is critical to the long term success of your tank. It is very easy to invest over $10,000 into a reef tank over several years and lose everything because you did not spend a few hundred for the "Just in case". Most tank disasters are not related to life threatening events. I'm not talking about earthquakes, tornados or meteor impacts. In such cases you have more to worry about than a fish tank. I'm talking about loosing power for a hours to a few days either due to ice storms, car hitting a pole, local energy shortage, etc.

In most cases a tank can go for about an hour or so with no power with little effect. However, once you start reaching around 45 minutes into a power outage you should start your disaster recovery plan. If you reach the point where worms are crawling out of your sand bed to get air you have likely waited to long and are in for a rough ride.

Depending on season you have two primary factors to worry about in reef tanks temperature and oxygen levels.