Saltwater Aquariums with Power Outages

Black and white striped fish in a tank

Aquariums (especially marine aquariums) cannot function without power, which is a harsh fact. Electrically driven air pumps, powerheads, protein skimmers, automated feeds, and lighting are among the devices utilized to keep your tank animals happy and healthy. Aquarium equipment, like practically other lighting and appliances in your house, relies on alternating current (AC) power for the most part. Your aquarium will cease working if there is a power outage.

Aquarium Needs

Gas exchange and water movement are two activities in a saltwater aquarium that are critical to its life. Even the most delicate corals in a reef tank may live for days without bright light, but without a sufficient supply of oxygen, the survivability of fish, crustaceans, corals, and beneficial bacteria rapidly deteriorates. As a result, in the event of a power outage, the aquarist's primary goal (both short and long-term) is to provide oxygen to the tank and move water about in it (even if just intermittently). Some of your tank's filtering devices (wet/dry trickle, canister filter) will not operate at this level of survival. If oxygen is given at least regularly, the nitrifying bacteria that dwell in the tank (on the living rock, tank walls, etc.) will live and continue to process ammonia, nitrites, and nitrates.

The great bulk of gas exchange (carbon dioxide out and oxygen in) occurs at the water surface of most tanks when they are running properly. During normal operation, protein skimmers and help with gas exchange, but they won't work if the power goes off.

Manual Aeration

In the case of a power outage, you can manually deliver oxygen to the tank and create some water movement. Here's an easy-to-follow solution that genuinely works:

  • Take any type of clean container and use it to scoop up some aquarium water.
  • Hold the filled container some distance above the aquarium, and pour the water back into the tank. Repeat this process numerous times.


  • You provide more oxygen by pouring the water from higher above the tank, the higher the better. You also provide more oxygen the more times you repeat the pouring.
  • You will know you need to provide more oxygen by manual aeration if the fish are coming to the surface gasping for oxygen.
  • To avoid messing up the substrate, place a small plate or bowl in the tank and pour the water onto this area.

Emergency Power

Adam Goldstein describes how his tanks have weathered several power outages, some lasting up to three days. Normal car batteries should not be used indoors because they release sulfuric acid fumes (which are harmful), but Odyssey batteries are sealed and thus safe to use indoors. Adam used two Odyssey 925 cold-cranking amps automobile batteries and a 400-watt DC-to-AC power converter. Adam was able to operate his usual AC pumps and filters with this configuration, but he did not turn on his tank lights (they used too much electricity). A solar panel might be used to replenish the batteries in his automobile while he was driving.

While keeping a gasoline-powered generator on hand may not be a feasible choice for many individuals, it may be the best long-term answer for coping with a power outage. To be sure, they aren't cheap, but for $400 to $500, you can get a 5,000-watt generator that can not only keep your aquarium(s) going but also power the rest of your home's electrical appliances. When you consider how much money you've put into your marine aquarium's inhabitants, it's easy to see how a $500 investment in a generator is relatively inexpensive insurance. Prepare for the worst-case scenario while hoping for the best.

If you do decide to buy a generator, you should carefully consider hardwiring an external 220-volt receptacle into your home's electrical panel. You won't have to keep a window open to accommodate all of the extension cords. Many of your electronic equipment will be able to be powered by standard outlets. When the electricity goes out, all you have to do is get your generator out of storage, plug it in, and turn it on. However, be certain that your primary circuit breaker is tripped. Otherwise, you'll be giving electricity to a large number of individuals via the power lines. If you are not familiar with electrical wiring, engage a professional electrician to perform the necessary changes.

If you don't want to make the investment on the off chance that you'll be faced with a long-term (more than a few hours) power loss, many retailers (Walmart is one) will refund your generator purchase if you return it in its original packaging.

No matter what your solution is to deal with a power outage, whether it is caused by a blizzard, hurricane or total power grid failure, the key to survival is to plan ahead.