Do You Know What To Do in a Fishtank Emergency?

Posted by Augusta Hosmer on

Read Time: 7 minutes

How to Keep Your Aquarium Safe in Power Outages, Natural Disasters, etc: Your Of-fish-al Aquarium Disaster Plan 

We like to keep the good vibes flowing at Dustin's Fishtanks, but in light of hurricanes, climate that needs to eat a Snickers, and everyone's favorite upcoming winter weather, there's a topic more folks need awareness on: what to do when times aren't so sunny. It's rare to find a detailed disaster plan in place for most families, much less for aquariums. 

If the power went out for a week right now, would you know what to do to keep your aquarium environment stable? If a fire started and your fish tank miraculously survived, what steps do you take to give your fish their best shot at making it and having a story no new fish in the tank will ever be able to top? 

If you failed this pop quiz, you're not alone. Most people don't think about it until after the lights are out. In this post, we'll give you some tips and tricks for taking care of your fish in emergencies to get you ready before it's critical. 

Common Mistakes/What Not To Do

1. Don't panic. A lot of the tips in this post are very easy to implement. 

2. If you have to evacuate and can't take fish with you, don't feed your fish extra on the way out. You're not going to give them any kind of advantage or give them a chance to free feed while you're gone. At best, you've wasted some fish food. More likely, you've overfed and your water parameters are going to go out of whack - the last thing you need when you're trying to keep a tank stable.

3. Don't worry about light too much (unless you have plants you want to keep alive). A darker environment will actually keep fish less active, which means they use fewer resources you're trying to make last. 

4. Don't do a water change that's too large, whether you're leaving or not, unless you have contaminants in your tank. You want to give your water chemistry a boost, but you also don't want to send your fish into shock due to a sudden drastic water change. 50% is probably the absolute max I'd do in this situation unless there was something contaminating the tank (like in the case of a flood or a fire). 

5. If you evacuate and decide to take your fish with you, be sure to not fill the containers/bags up all the way. Leave some room for oxygen. (~1/3 water, 2/3 air). And if you're traveling long-distance, have a way to introduce oxygen into the water, whether it's with a USB air pump or simply agitating the water surface at regular intervals.

6. Don't beat yourself up if you can't save your aquarium. The fact that you're reading this means you want to do what's best for your fish, and these are all great steps to take. That said, there are some situations where there's nothing you can do, or where you have to make a choice between taking care of you/your family or your tank. Don't put yourself at risk, and don't feel guilty about that afterwards. 

Your Main Concerns: Temperature, Water Chemistry, and Aeration

No matter what the disaster is, your two immediate worries are temperature and oxygen in the event of a power outage. If you have a larger tank, you have more leeway because it won't change as rapidly. Chances are, if you're only in a situation without power, etc. for a few hours, you'll be okay without a lot of intervention. Definitely still monitor, but don't worry too much.

But if it goes beyond that, you need to maintain temperature and circulate oxygen, especially if you're in an area with widely fluctuating temperatures. After a while (especially if you haven't done a water change recently) you also have to worry about keeping your water chemistry stable (avoiding ammonia spikes, killing your beneficial bacteria, etc).

Best Practices in an Aquarium Emergency


If a disaster causes a power outage for an extended period of time, it's essential to monitor your tank's temperature, even if you have a generator or a power source for your heater. An accurate aquarium thermometer is your best friend.

If you're in a winter weather emergency where the temperature will drop rapidly, insulate your aquarium with blankets, towels, or an emergency "space" blanket to prevent heat loss.

If the temp still drops and you need to add extra warmth, you can either float a heat pack in a container (never put it directly in your water) or attach them to the outside of the aquarium. If you still have access to hot water, you can also add warmer dechlorinated water to your tank. If it goes the other way and you need to keep your aquarium cool in a hot environment, you can approach the problem in a similar way, but with ice packs and cooler water. Just be sure to change the temperature gradually to avoid shocking your fish. 

If it's possible to safely move the tank, moving it to a central part of the house away from windows/doors can help as well. 

Filtration/Water Chemistry

Filtration isn't the most pressing concern in an emergency situation, but keeping your beneficial bacteria alive and avoiding harmful chemical spikes is still important. If you have a filter that isn't already in the tank (like in a hang-on-back filter), take out your filter media and submerge it in the tank or pour tank water into the filter occasionally to keep it moist/keep your bacteria alive. You also will need to do more frequent water changes and water testing to make sure your water is staying within the proper parameters. 


It's better to underfeed in an emergency than overfeed (Well, it's better to get the right balance, but if you had to pick which direction to go). Feed as much as required to keep your fish healthy, but limit it as much as possible. You want to avoid introducing things to your tank as much as you can when trying to keep it stable.


Fish need constantly circulating oxygen. With no power, your air pump and filter aren't providing that. Fortunately, have a few options. One is agitating the water's surface occasionally by scooping up water and pouring it back into the tank to simulate the action of a filter. It's not perfect, but it's better than letting the water sit stagnant. You can also get a battery-powered or USB air pump. 

Evacuating/Transporting Fish

If you decide to evacuate and take your fish, keep space in the container as mentioned above so your fish have oxygen. Make sure you have a plan and necessary supplies for taking care of your fish at your evacuation destination, and look for supply sources in your new location ahead of time if possible. If you can get an air pump that works in your car, providing occasional aeration to the containers increases likelihood of fish survival. It's also a good idea to bring extra treated water with you and check on your fish frequently. 

Fire Prevention

A bunch of cords plugged into two power strips

One common question with these scenarios is whether a fish tank will survive a fire since it's mostly water. The answer is "sometimes." But even if the tank itself makes it, you need to worry about contaminants from the fire and smoke. The biggest factor with fires is prevention. Funnily enough, one of the most common causes of house fires is aquariums. Check your equipiment regularly and avoid getting water on electrical components (duh). Don't overload your outlets, find ways to waterproof your electric components, have proper drip loops, and so on.

If a fire does break out and your fish miraculously survive, water changes and filtration are crucial to avoid fish death because of water toxins introduced by the fire.

What to Have Ready Beforehand/Emergency Kit Checklist

One thing everyone with any kind of pets should have ready is a set of easily found/accessible care instructions. These should be detailed and written in a way that someone with no experience with your animals could safely follow them. You could even go so far as to label your equipment.

I have all my animals' daily, weekly, monthly, and emergency care written out on a whiteboard in an obvious spot on my fridge, and I have a binder with even more information and records. These include info on species, care basics, ages, dates of last water change, etc. On one hand, it serves as a good reminder for me for stuff I don't do as often. On the other, in the event something happens and I can't get home, someone else can come in and take care of everyone. 

It also helps to practice emergency situations before they happen. Think of it as an aquarium drill. Going through the motions of a pretend disaster can identify problems you didn't know you didn't know about. It's also a good idea to get comfortable catching your fish before you're in a stressful emergency situation. This seems like a simple thing, but if you've ever tried to catch a zebra danio with a tiny net, you know what we're talking about. Some fish are ridiculously fast and will have you ready to turn them into fish dinner when you finally catch them. Knowing the catching strategy that works best for you ahead of time? Golden. 

Having an emergency kit made before disaster strikes is also essential. Even if it's not feasible to keep everything on this list on hand all the time, just having a few set aside or knowing what to grab in the event you have advanced warning of a disaster can save you a lot of stress. 

A USB Aquarium Pump
A USB Aquarium Air Pump

Emergency Kit Checklist:
-Extra supplies (fish food, water conditioner, etc.) if you can spare them
-Something that can be used for insulation (blankets/towels, Mylar "space" blankets, etc.) 
-Bucket/Containers of some sort (even bags/rubber bands would work in an emergency as long as you're monitoring water) in case you have to move your fish from hazards in a tank or transport them
-Premade tank water for water changes in case you lose water access
-Water testing kit
-Heat packs (never put them in your tank - but you can attach them to the outside to heat up a tropical tank if needed)
-Ice packs, ice, or some other means of cooling (again, don't put directly in the tank - can float it in a secure bag or attach outside)
-A printed copy of care instructions and/or a printout of guides like this one
-Extra batteries 
-A USB/battery-operated air pump w/ tubing and air stone (just for advanced warning, these things can get kinda loud depending on the brand, though they're working on making them quieter). 
-Some way to catch your fish (net, etc.) 
-A generator would be make things a lot easier (for your fish AND you) You can survive without one, but definitely consider one for emergencies. 
-Tape (duct tape is magic)
-Aquarium silicone, Flex seal, or some other kind of sealant (can be useful in the event of a small leak)

It's impossible to be prepared for everything, but we hope this info makes you feel more at ease and more prepared to deal with disasters. Though it's not always possible to save your tank, with these tips, you can give yourself a fighting chance.

Questions? Comments? Ideas for another post? Cool Halloween tanks? Let us know. Stay safe out there, and tank on!

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