Resource Center Menu
Caring for Your Aquarium During a Power Outage

Caring for Your Aquarium During a Power Outage

You’ve done everything you can to ensure your fish have a happy and healthy environment. Their aquarium is a well-established living space outfitted with all the appropriate pumps, filters, heaters and lights necessary to provide an optimal ecosystem — but what happens when the power goes out? Here’s what you need to know about keeping your fish safe in the event of a power outage.

What happens to your aquarium and fish during a power outage?

You likely already know that power outages come in multiple forms and can last anywhere from less than a minute to hours or even days. The briefest of outages usually occur when a power grid is accidentally or temporarily shut down, your circuit breaker has issues or, in the most easily fixed case, the aquarium power cord somehow gets unplugged. Other outages caused by weather or natural disasters may take longer to get fixed.
 
An outage that lasts three hours or more could become problematic for your aquarium. This is because most modern aquariums use electricity to run all of the essential parts that keep it stable, like those pumps, filters, heaters and lights mentioned before. Without electricity to keep all of those moving parts functioning, the environment in your pet’s aquarium become unsettled very quickly. Without power, the most common issues to occur in an aquarium include:

  1. Oxygen depletion. Your fish will still consume oxygen in the aquarium, even if that oxygen isn’t being replaced with the help of your filter. As the aquatic life in your tank slowly uses up what’s left, a dangerous oxygen depletion will start to occur.
  2. Water temperature variation. Most aquatic species need water temperatures of 72 to 82 degrees Fahrenheit to remain healthy. Changes in water temperature may stress your fish, which then puts them at risk for disease. Additionally, as temperatures rise in the aquarium, water begins to lose its capacity to hold oxygen.
  3. Ammonia buildup. Without a working filtration system, the ammonia in your aquarium could reach levels that are toxic to your pets.

Preparing your aquarium for a power outage

The best way to prep for a power outage is to have a solid backup power system in place. For your aquarium (and other important household items), consider having an uninterruptible power supply such as a generator on hand. You can purchase one of these through most office supply stores.
 
During a shorter power outage, you may be able to mitigate any aquarium issues by using a spare battery-operated air pump and keeping a good supply of batteries on hand. This will provide the necessary oxygen replacement and water movement in your tank until the power comes back.

What to do for your aquarium during a power outage

If your power goes out, complete the following steps to ensure that your fish remain safe:

  1. Check out the aquarium and other powered devices to see if the power has gone out all over your house, or if it’s only in some areas and your aquarium is still running fine
  2. If you have an uninterruptible power supply setup, ensure that it’s running properly and is supplying back-up power to your aquarium
  3. If you have a battery-operated air pump, place it in your tank, ensure that the batteries are new, and start it running (keep backup batteries nearby)
  4. If you’re using a battery-operated pump and your power is out for longer than five hours, complete a 25 percent water change to help keep water quality safe
  5. During the summer, you can float bags of ice cubes to add cool water and stabilize the temperature and oxygen content
  6. In the winter, wrapping the tank with a blanket — taking care to avoid covering the top — can help to keep the water warm
  7. Avoid feeding your fish when the power is out. Most fish — especially typical aquarium fish — can go multiple days without eating, and feeding during a power outage will increase the activity level of the fish, as well as their waste, which causes an accelerated loss of oxygen and a buildup of harmful ammonia and nitrites.
saltwater fishtank

Caring for your saltwater aquarium during a power outage

If you have a saltwater tank, you’ll want to ensure that many of the same systems are accounted for, including maintaining oxygen levels and keeping a system of moving water. Most saltwater fish can last for days without light, but maintaining oxygen levels is important. Without the help of an uninterruptible power supply, you can manually help supply oxygen to the tank and keep water moving by filling a cup or pitcher with tank water and pouring it back into the tank. Doing this — for a few minutes at a time every 10 to15 minutes — helps add oxygen to the water as well as circulate it through the tank.
 
A little preparation and forethought can go a long way to ensuring that your aquarium remains in a stable condition and continues to provide your fish with everything they need to ride out the outage.