Aquarium Maintenance: Surviving a Power Outage 10

Share This On


The worse thing that can happen to any home aquarium is a power outage.

Whether it is an hour or multiple days, it can create havoc and possibly kill your fish if the correct steps are not taken during a power failure.

This might even have a beginner hobbyist think that having an aquarium is too much hassle if a power failure occurs.

As with everything in life, it’s always best to be prepared for the worst.

So, in this post I will try to go over the numerous steps and tips on what to do when there is a power failure.

Unplug All Filters

Unplug sockets

Unplug Filters

The first thing is to unplug all filters!

Some canister filters, especially older models can siphon water from the tank and leak out of your filter creating water damage.

Another reason to unplug your filters is because harmful toxins can buildup in your filter if your power is off for a long period of time. These toxins include ammonia and hydrogen sulfide.

When the power comes back on, these toxins will go back into your aquarium posing a deadly result to your fish and inhabitants, especially the delicate species like ornamental shrimp.

To avoid any type of toxins entering your tank rinse out the filter and all its contents before powering back up.

The next thing you should do is protect your biological filter by placing items such as biowheels and ceramic stones in your tank and submerging them below the water line.

For trickle filters, pour water in them occasionally and wrap in a plastic back for them to keep their humidity and for those that use the fluidized bed filters, leave a ¼ – ½ of water above the sand and remove all of the other water from the unit.

If you are not home while the power is off and it comes back on before you return home, it would be wise to do a 25-50% water change just in case any toxins built up in your filter while the power was off.

Restore Oxygen Supply

Next is giving your fish oxygen, or water movement to produce some oxygen at least. \Your best option is to keep a battery powered air pump as a back up for situations like this.

The battery powered air pumps range from around $5.00 to $75.00 depending on where you purchase it from. Some of these come with an electric charger so if the batteries do go bad, you can recharge it if you have a generator.

There are two types of battery power pumps where some will run on D-cell batteries and some run on 12 volt car batteries.


Recommended: Penn-Plax Silent Air B11. Enjoy a 14% discount on Amazon HERE.

If you have no battery backup, the least you can do is take a cup or small bucket and fill it up. Then hold the cup about 6 inches from the water surface and dump it back in to make bubbles form.

Another inventive method that I’ve heard hobbyists doing, is hooking some airline tube to a bicycle air pump. Then they install an airstone on the other end and hand pump the bicycle pump for a few minutes every so often to create oxygen.

At the VERY LEAST, you could also just agitate the water with your hand, net, or algae scrubber.

Remember: The worse thing in a power failure is the depletion of the oxygen levels in your aquarium.

Maintain Water Temperature

aquariumthermometer1The next thing on your list to maintain will be the water temperature of the aquarium. Glass is a poor insulator so water temperature heat loss can occur fast.

In cold winter months, this can happen rapidly and create stress on your fish or even kill them. Fish will adjust to slow temperature drops, but not rapid drops in temperature.

The fastest thing you can do to prevent heat loss, is to put a blanket over the top and around the unit.

Make sure your light is switched off or unplugged. Especially if you won’t be home, as should the power comes back on, the heat from the light may create a fire on the blanket.

If you have any alternative heat sources (gas range, gas or kerosene space heater, wood, pellet or corn stove), you can also heat water in a pan for a few minutes. Just remember not to heat it up to a boiling point.

Use a thermometer to gauge the water temperature and then pour the water into plastic jugs or glass jars and float them in your aquarium. This is time consuming and would have to be done multiple times during an outage to keep the temperature in the aquarium from changing too drasticly.

If you want to go the extra mile, aquarium thermal blanketing is a great option in retaining heat in your aquarium. This does requires a little more more work but is one of the the best ways to keep heat loss to a minimum.

This requires going to your local home store or favorite online retailer and getting Styrofoam sheets. Cut them to size to fit around your aquarium and tape the seams together for a more thorough insulation. This will help prevent any cold air getting in and reducing heat loss.

Another form of insulating by blanketing is using the thermal blankets themselves. These are more expensive but come in one complete roll and you just cut it to size. These are normally used to keep your hot water heater insulated better if you have it in a cold basement.

The wrap is also a good insulator on your aquarium; the difference is they are more widely available. I have seen these for sale at department stores such as K-Mart, and Wal*Mart.

Also do not forget to insulate the bottom of your tank as well if it is exposed. My personal opinion is even if it is covered by a thin piece of wood or metal, it would not hurt to insulate it anyway if your budget allows. Punch a hole in the top so you can stick your airline in the aquarium for aeration and you are set to go for days without power.

Takeaway: Avoiding a rapid change in temperature is crucial in a power outage to avoid unnecessary stress to your fish(es).

Other Notes

Here are few more notes you should know about how to survive a power outage.

Firstly, you shouldnot feed your fish. They can live 3-5 days without food but if you feel like you need to feed them, feed them sparingly. Food that has gone uneaten will absorb a lot of oxygen therefore depleting your aquarium faster.

Some fish also demand more oxygen then others and removing those oxygen demanding fish to a buck would be easier to do water changes to keep the oxygen level higher for them.

Remember: Never overstock or overfeed your fish as this will create a faster oxygen depletion as well.

If you have used any medications or aquarium salt, remove the salt right away.

If you’re expecting a power outage due to a storm coming, do a 40-50% water change to get rid of the medication from the aquarium.

If the power goes out suddenly and you do not know when it will be back on, after about 2 hours it would be wise to start carrying out these power outage operations. You can also contact your power company for an estimated outage restoration.

This will make your fish gasp for air and your beneficial bacteria starts to deplete and this will also spike your ammonia which will ultimately result in fish loss.

Your Experience

Have you had any experience with power failures with your aquarium?

Any tips to share?

The Home Aquaria community would surely love to hear your tips in surviving a power outage, so be sure to share it in the comments section below.

About Dennis Hanson

Dennis is an experienced aquarist with many years of knowledge and experience in keeping successful tanks. He also has no relations to the pop group Hanson.

10 thoughts on “Aquarium Maintenance: Surviving a Power Outage

  1. Reply Absolute Aquarium Maintenance Apr 16,2014 7:50 pm

    I have lots of power outages where i’m from, if its just a couple of hours I typically do nothing as there is generally no problem with that, if it is more than that I have a backup generator that I use.

  2. Reply Justin P Jun 8,2014 12:07 am

    I went to Office Max and Bought a $150 Uninterruptible Power Supply. Get the one with a Screen that can tell you how long the battery will last while unplugged. Mine will run the air and filter for 2 hours. add the heater, runs about 45 minutes in winter. remember to change the battery in 4 years.

  3. Reply Tanner c Jun 5,2015 4:39 pm

    You can also keep a corner filter and a battery powered air pump as backup and when You lose power just set up the corner filter in the tank and place your bio media from your filter into the corner filter and this should help both your ammonia and your aeration. just some ideas…

  4. Reply Dan Mar 11,2016 8:33 pm

    A 1500 watt inverter charger is great for aquariums during a power outage. The inverter automatically switches over to inverter mode when it senses a loss of power. This article has some useful information:

  5. Reply Lee Howland Apr 1,2016 9:41 am

    Another good way of insulating your tank is with a fire blanket. It lessens the risk of fire due to power surges. Also another blanket I would suggest is one that ambulances use to warm up a person in shock.
    Hope this was helpful. Lee

  6. Reply Rachel Feb 10,2017 7:44 am

    Yesterday we had a power outage for 10 hours and my phone ran out of battery?! Eek! Having to think fast, I used a small battery operated facial fan, put it on its side and rigged it up with duct tape to create bubbles across the surface. Luckily for the fish it was a darn hot day and thank goodness I had enough batteries! I couldn’t believe it. Worked like a gem. 🙂 We still have a happy fish. 😀

  7. Reply Rachel Feb 10,2017 8:15 am

    Oh and thanks everyone for the initial post and comments!! I will let the fish owner know for the future reference. It was a scary day yesterday for me and Gaz. I love him even though he’s not mine. 🙂

  8. Reply Angela Z. Apr 13,2017 7:18 pm

    Hand warmers ! were I live when winter is ending large boxes of hand warmers become available at a bargain price. Designed to fit in your pocket and to last up to 18 hours I have found that they are very effective for smaller tanks (10 gal or less) or mini tanks especially when used in combination with blanketing. For best results and maximum heat output you need to shake them every couple of hours as the element used is oxogen activated. The best thing is that they can be kept in storage until they are needed. Also great for warming baby chicks!

  9. Reply Gerty Gift May 17,2018 3:37 pm

    Thank you for the advice about keeping the water temperature warm by covering the aquarium in a blanket. We just recently bought an aquarium for our girls and we’re trying to teach them how to take care of the fish. I think that also knowing this bit will help them to be prepared to take care of them in emergencies.

Leave a Reply




This site uses Akismet to reduce spam. Learn how your comment data is processed.