An aquarium is safe for some time without filtration when the power goes out, but the inhabitants cannot survive for very long without oxygen. When you do not have a battery-operated air pump or an emergency power source to run one to provide a steady source of oxygen to your aquarium in an emergency situation, it's easy to do so manually, and at the same time keep the water circulated.
A quick word about battery powered air pumps: Most battery-powered air pumps are not very powerful and will not drive air very far into the tank. Before you rely on these pumps, test them before you need them in an emergency. The best and most reliable battery back-up air pumps are the ones which run constantly on AC power, then automatically switch to the air pump's internal rechargeable battery when the power goes out. These work very well if you don't happen to be at home when the power goes out.
- Take any type of clean cup, pitcher or another container, scoop out and fill it with aquarium water.
- Hold the filled container some distance above the aquarium, and pour the water back into the tank. Repeat this process numerous times.
Tip: A larger volume of oxygen is generated the higher the water is dispensed from above the aquarium, and the number of repeated times this is done.
More Oxygenation Tips
- There is no set rule on how often this should be done because every aquarium is different. You'll need to judge for yourself at what intervals each hour is going to be best for your system. When in doubt, go ahead, and if the fish start coming to the surface gasping for air, it's definitely time to aerate some more.
- To avoid messing up the substrate and stirring up a bunch of crud, particularly if you have a small or shallow aquarium, place a small plate or bowl in the tank and pour the water onto this area. Ceramic or glass items work well for this because the item has to be heavy enough to stay submerged and in place.
- If you are using the floating hot water container method to manually generate heat in the aquarium, periodically pour some of the water over the top of the containers. Remember, heat rises. Most of the heat generated from the floating containers will stay near the surface, so this is a good way to get the warm water circulated.
- If your system ends up being shut off for a long period of time, due to the lack of filtration it's important to periodically test the water for any sign of ammonia. If ammonia does start showing up, you can be ready to handle the situation to prevent ammonia poisoning by having an ammonia reducing product such as Kordon's AmQuel on hand.