My Power is out – What do I do with my Aquarium? What do I do with Reptiles?

With Hurricane Sandy making landfall last night I figured now would be a good time to write a post about what to do with your Aquariums & Reptiles during a power outage. I myself have gone through numerous power outages while keeping fish and reptiles and it isn’t a fun experience for anyone. The good news is that all of your fish and reptiles will likely be fine, especially if your aquarium was in good working order. If you keep up on water changes and your nitrate levels aren’t through the roof a few days without power should not be detrimental.

I’ve written out the procedure I followed during an extended power outage a few years ago. I am glad to report that I didn’t lose any fish during that time even though my aquarium temperatures plummeted to as low as 50 degrees. Some of them were certainly not looking the best laying on the bottom of the tank but then again I don’t expect tropical fish to be swimming happily in cold water. They just sort of hibernated at the bottom during the cold, once the power was back on and the water warmed up everyone was back to normal in a matter of days. I did numerous water changes in the days following the return of power, you’ll want to do the same if your power was out for an extended time. The tank will start the Nitrogen cycle all over so the water changes will help keep the Ammonia levels down while the Beneficial bacteria builds back up.


  • Fish & Reptiles – Stop feeding them immediately. The food may be eaten but it is best to stop feeding during power outages in my experience. In the case of reptiles they probably won’t eat due to the cooler temperatures, if the power is out so are the heat bulbs you likely have. It won’t hurt most healthy reptiles to fast until your power is back on. In the case of Aquariums, you do not want to add anything to the tank while it is not running. Any uneaten food will begin to rot and without filters to help break down the uneaten food it will foul the water quickly. So just avoid any feeding until the power is back on. Once it is back on you’ll want to give the fish & tank a day or so to stabilize before feeding.
  • Reptiles – There isn’t a whole lot you are going to be able to do for most reptiles. The main items that they require are all dead when the power is out, namely heat lamps and UV bulbs. The UV bulbs being out are hardly going to hurt anything being off for a few days. The heat lamps however are typically required to keep the temperatures stable. Once the power has been out for a while the reptile enclosures temperature will fall to whatever the temperature in your home is. Unless it is extremely cold most reptiles will do fine. Just leave them be and don’t try to feed them during this time. They will sit there dormant just as they would during a cold snap in the wild.
  • Aquariums & Fish – I have had dozens of fish survive 4 day power outages during which time my home was just above 40 degrees throughout. I had no way to heat the tanks of filter them, I simply did not feed and changed a bit of water each day in the tanks. If you’ve got a super complex Saltwater aquarium with corals and other sensitive life forms you may be in a bit of trouble without a source of backup power. It is especially hard because you can’t just do a water change either unless you keep premixed saltwater around. If you’ve got a Freshwater tank then begin doing partial water changes (10-20%) after the first 12-24 hours have passed without power. This will help keep the water oxygenated as well as the ammonia down. As the tanks sit without filtration the beneficial bacteria will begin to die off, causing the Ammonia levels to spike. This is why you must do water changes daily or even numerous times daily to give your fish the best chance at survival. Without heaters the water temperature will fall but this is ok, most tropical fish can survive short periods in cool or even cold water, so long as the change is gradual. So if you can only change the water with cool water that should be fine, just don’t do too much at once. You’ll want to make sure you add some sort of treatment as you would during any normal water change. This will not only help make the new water safe but it will also help keep the fish safe during the Ammonia spike which will happen during the power outage.


  • Keenan says:

    Hi there! This is my first comment here so I just wanted to
    give a quick shout out and say I truly enjoy reading through your articles.

  • Denise says:

    Our power was out a week,Ohio, had a 55 with 10 yr old huge clowns and silver dollars and no battery backup and just an under gravel filter. Oxygen was running out. Then someone told me add around 2 tablespoons of hydrogen peroxide. No more gasping. Didn’t lose anyone. If you really get desperate separate them in pickle buckets keep changing the water to dilute the ammonia . Use warm water.

Leave a Comment