How To Survive A Fish Tank Power Outage – Read This To Save Your Pets!

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The most dreaded event in our hobby is a fish tank power outage. I write this article with a heavy heart as a good friend of mine just lost his reef tank of over 11 years after the snowstorms here in Texas. He had a wonderful 150 gallon reef tank and within a few days everything was gone!

I don’t want you to go through the same thing and hopefully you are reading this before you had a power outage. It’s a horrible and helpless feeling. I also feel this should have been one of the first articles I wrote when I started up this blog. Either way, I’m here to guide you and get you prepared. I’ll cover it all. I’ve been in your shoes and have survived several here in Texas. It’s an all too common event here with our weather.

Why Is An Aquarium Power Outage So Deadly?

Let’s start with this first question. For the vast majority of pets that we know of, most will be unaffected by a power outage. A dog will continue to be your companion and a cat will happily hunt for its own food if things get very dire. Both pets in these cases continue to have free unrestricted reign to their space.

The live animals in your aquarium do not have this privilege. They are in a closed environment – their aquatic world. Everything in your aquarium requires the ecosystem to be stable. When the electricity goes out, the entire system is thrown off balance. Air pumps and wavemakers move water and oxygenate it. Your power filters and sump maintain your nitrogen cycle and keep your bacteria colonies going. If you keep live plants or live rock, these lifeforms provide filtration and need your fish happy and healthy to function.

Electricity is the heart of the your artificial ecosystem you have created. Without it, the life support breaks – and it gets ugly and tragic very quick

Why You Need A Backup Plan

Let me highlight the story of my friend. Below is a picture of his tank before the snowstorms here in Texas. 11 years of building his reef tank down the drain in a few days. He didn’t have the equipment to get through the power outage. Most people with tanks this large don’t. I don’t spare you the aftermath, it’s not for the faint of heart

Aquarium Power Outage

Let’s talk about everything that goes wrong during a power outage

Oxygen Levels

This is the primary concern when you have a power outage. Oxygen will be the first thing the depletes in your aquarium. Once your air pumps, wavemakers, and return pumps power off it’s a race to keep your oxygen levels up. Within a few hours of no water flow, your oxygen levels will deplete and everything will start to suffocate. It gets ugly very quick.


This is the next killer. This is what I call the long-term killer when power outages last for days. Depending on your climate it will either be a cold tank or one that overheats. Cold weather is actually either to deal with because animals in aquariums can handle colder weather for some time. They will go dormant or slow down. I have seen reef tanks go through cold temperatures for several days hitting low 60s and the corals and fish pop right back up after the power comes on.

Heat is a other other matter. It makes a lot of sense as we have see mass bleaching events in our oceans when temperatures rise only a few degrees1. This is the same with freshwater fish. Heat kills aquatic animals fast. And it doesn’t take a power outage either! A failed AC and 85+ degrees in your home and your apartment is dangerous for your fish tank

Ammonia Spikes

Once animals start dying, there will be massive ammonia spikes. Your bacteria colonies, which are handicapped during an outage will be overwhelmed at the increase in ammonia. It will be like dominos falling. Once something dies, everything else will start doing so quickly!

Get Your Gear Now – Don’t Wait!

I’m going to provide you a quick shopping list of what you will need that covers different sizes of fish tanks and needs. I will go over why each one is effective. Get this gear now before disaster strikes. You owe it to your aquatic animals

For Large Tanks
Champion Generator
Champion Generator
  • For large tanks
  • Long-term power outages
Buy On Amazon
Requires No Electricity
Dr. Sochting's Oxydator
Dr. Sochting’s Oxydator
  • Requires No Electricity
  • Removes Ammonia
Buy On eBay
Most Portable
AmPeak Car Inverter
AmPeak Car Inverter
  • Works on Cars
  • Long term outages
Buy On Amazon
For Small Tanks
Penn Plax Battery Powered Air Pump
Penn Plax Battery Powered Air Pump
  • Battery Powered
  • Small Tanks
Buy On Amazon
For Wavemakers
IceCap Battery BackUp
IceCap Battery BackUp
  • Battery Backup
  • DC Wavemakers
Click For Best PriceBuy On Amazon


I’ll go over each piece of equipment and explain what they are best for

1. Generators

Generators are the best solution for a long-term power outage. A lot of aquarium stores and retailers do not like to talk about them because they want to sell you their aquarium based solution, but the fact of the matter is an old school generator will get you through the worse power outages.

The one I linked to is an all-rounder that will work for virtually any situation and setups. I know some hobbyists who have so much invested in their tanks, that they have purchased a whole home generator. These are very expensive and out of the budget of most folks. They run off gas that you can get from a gas station or siphon from your vehicles. A full tank should run you about half the day. If you don’t purchase one for your aquarium, you should consider getting one for your house as part of your diester planning efforts

2. Dr. Sochting’s Oxydator

This has been my secret weapon for years against power outages. This amazing piece of equipment requires no elecricity to operate. It functions by using a catalyst and hydrogen peroxide. The chemical reaction creates oxygen for your aquarium and detoxes ammonia from your aquarium. This can efficiently replace your biological filteration and keep your tank full of oxygen during the outage

Since they do not require electricity to operate, they are ideal for long-term power outages. The hydrogen peroxide will last 5-7 days and it’s easy to buy the solution in bulk and stock up. They are hard to find though. They are best ordered through EBay or get one now while you can wait on shipping

3. Car Inverter

This is another unconventional solution for an aquarium, but also way more efficient than what other retailers tell you. A car inverter converts the DC voltages in your car’s battery into AC power for your devices. You can keep your car on to keep your battery charged. Because your car runs off gas, this is another long-term solution and also a portable one as well.

If you own multiple cars, it’s easy to switch between cars as you need power and if you run low on gas you just go to the gas station to get more

4. Battery Air Pumps

Battery powered air pumps are ideal for smaller tanks. All they require is C or D batteries and are very affordable to purchase. They are one of the easier go to solutions when it comes handling a power outage. Batteries usually last about 8-12 hours and can be replaced with a supply that you can store.

Every aquarium should have one of these. They come in handy in a pinch

5. Battery Backups

This is the most common solution retailers will offer to you. It makes sense, most are made by aquarium equipment manufacturers. They have their place and will last several days.

You will also see other options people will throw out like a Uninterruptible Power Supply (UPS). The problem with these is they are not designed to power aquarium equipment for long. They will using give you a few hours of power. The backups designed by aquarium equipment manufacturers are a better choice.

Still though, battery backups aren’t effective for long-term power outages. I’d rather go with the combination of a Oxydator and generator to keep my tank going.

How To Aerate Fish Tank Without Electricity

Okay, so maybe you have come across this post and you have no equipment and you are on your phone trying to figure out what to do. If you lack equipment, here is the best way to low tech your way out of a power outage

Low Tech-ing Oxygen

  • Get a bowl and scoop water out of your water and poar it back in
  • Use the same bowl to move the aquarium water across like a pump and create air bubbles
  • Repeat this process every 15-30 minutes

Keeping Your Water Warm

  • Get thermal blanks and cover your aquarium in it
  • If you do not have these blankets, use any other blankets you have around the home
  • Huddle up the family near the aquarium too bring around body heat
  • Pour hot water into the aquarium slowly to raise the temperature – make sure this water is de-chlorinated

Keeping Your Water Cool

  • Get ice out of your freezer and put it in a container
  • Put this container into your aquarium to cool your tank
  • Refill the container with more ice as it melts
  • Continue doing so to keep the temperature down
  • Remove your tank hood or open your canopy if you have one

Common Questions

How Long Can Fish Survive Without Electricity?

Not very long. If you have not backup equipment, it can be as little as 2 hours before your fish run out of oxygen in your tank and they start suffocating. If you do not invest in a power outage solution your cherish pets can perish within a few hours after the power goes out!

Can Fish Survive Without a Filter?

They actually can if you invest in a power outage solution. An Oxydator will keep your aquarium’s oxygen’s levels up and will provide ammonia detox. If you have a battery backup or generator, your equipment will run during an outage

Will My Fish Die If The Electricity Goes Out?

Yes, they may very well die if you don’t take proper action! Get the proper equipment like battery powered air pumps or a generator if you have a larger aquarium. Flow the low tech plan of pouring and moving water to keep oxygen levels up and keep your temperatures stable.

Will Tropical Fish Die Without A Heater?

Yes, they can. However, cold is a slower killer to fish versus heat as fish will attempt to go dormant in the event the temperature drops low in the short term. You should take action in trying to keep your tank warm during a power outage. Most fish should be able to survive mid 60 degree temperatures in the short term. Just take the steps needed to in order to keep your tank as warm as possible. There is no heater that runs well in an outage as they draw a lot of energy.

How Can I Oxygenate My Fish Tank Without Electricity?

There are multiple ways to do this. Battery powered air pumps are the usual go to. A Sochting Oxydator is another great tool that will run for weeks without electricity while also removing ammonia. A low tech way of oxygenating without electricity would be to move the water manually every 15-20 minutes to keep oxygen flowing in the tank.

Still Not Sure What To Do? Ask A Question Below

We supplied a video below for reference from our YouTube channel. If you find our content helpful, please subscribe to us as we post new videos every week.

I know it’s tough and I know it’s heart breaking to experience a power outage tragedy. I’m here to help. Don’t be afraid to reach out in the comments below, email me, or even call me on my business line on my site’s foot below. I’ve survived several of these successfully in the past so I know what it feels like to be in your shoes. Best of luck for you and don’t be afraid to reach out.


  1. I have a 62 gallon freshwater tank with a high bioload. it was due for a water change anyway, so I started there. One thing I am using is my coffee frother to aerate! sometimes you have to use what you have. also, dunking pitcher in to tank and pouring it back in. my goldies are huge. they are tolerant of a lot of things but still need more oxygen. highly oxygenated water maintains them even better than extra filtration.

  2. We had it happen last night. We were on a generator since morning then that night our generator died. We have 2 tanks one with a crayfish and one with 5 neon tetras. So we covered neons tank with towel and and a towel on top of crayfishes tank and removed enough of water that crayfish could lift up head to breath .Then we used tin cans with tea light around both tanks. For the neons we poured 75 spaghetti Jars of water to make bubbles every 15 minutes we did this 6pm to 3:00 pm the next day . I just set timer in between pours . When tea lights went out tried back heat up thingies had to put on my back to start but it didn’t last. So went out and boiled pots of water and put Glas Jars of war waterwithcrayfishand plastic bottles in neons tank. Repeated 4 times and always found them Huddled around Jars even the snails. They are doing fine now but didn’t move too much when all this was going on.

  3. Just got through a 40 hour outage… Was using a pitcher to pour water through the filter and to make bubbles on my 90 gallon. Throughout the day I did it about every half hour, and through the night (two nights!!) I did every hour. Setting an alarm to wake up and everything. Did water changes a few times a day with hot water. Didn’t lose anyone but omg I do not want to go through that again…


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