You’ve probably heard the old saying “Failing to plan is planning to fail.” It may seem like a cliché but it’s really true. Hopefully you have a spare tire and jack in your car. No one wants a flat tire but having a spare really comes in handy when you need it. It’s the same with a flashlight. It’s smart to keep your LED flashlight plugged into a charger and ready to use. We’re even being told it’s a good idea to have a little reserve of food and water on hand. Having an emergency plan doesn’t make you a Doomsday Prepper! It’s just a small “safety net” to provide some protection against unforeseen circumstances. Emergency planning makes good sense if you’ve got an aquarium full of fish, corals and other aquatic life. Our aquariums are completely dependent on us to make sure life-sustaining parameters are always met. Power interruptions and equipment failure could have a serious impact on your aquarium. Let’s take a look at each component in your aquarium’s life support system and see how we can create a back-up plan for aquarium emergencies.


Electricity use goes unnoticed until you get the electric bill. All of our aquarium’s equipment, like heaters, pumps and lights need electricity to operate. If you live in area where there are frequent power failures due to wind, snowstorms or other environmental causes, you’re used to occasional or seasonal outages and the inconveniences it causes. For some of us, we don’t even think about power problems until we see the wind, rain, ice and snow. So, what can we do to prepare? You may be familiar with small battery back-ups for home computers, UPS or uninterrupted power supply. These are designed to keep your device running long enough to save your work and safely shut down the computer, but most of these units don’t have enough power reserve to run vital aquarium equipment. Fortunately, there are several-purpose-built battery back-ups made specifically for aquariums. We’ll talk about these in detail in the next section on water movement.

Water Movement is Critical!

More than anything else, it’s critical to maintain water movement in your aquarium. Water movement keeps the surface of the water agitated to promote the exchange of oxygen and carbon dioxide. Gas exchange happens at the water surface. Rapid movement helps oxygen to diffuse into the water and carbon dioxide to leave the tank. Water flow is especially important in reef tanks. Marine life like corals and the millions of beneficial microbes living in the live rock need constant water flow to bring in oxygenated water and flush away wastes like ammonia and carbon dioxide. If your main water pump or power filter were to suddenly fail, would you have a back-up ready to go?

aquarium gas exchange and emergency plan back up battery and air pump setup diagram

If you’ve got a small aquarium, a spare back-up water pump won’t break the bank in your plan aquarium for emergencies. Reef aquarists with larger aquariums normally have a main return pump and one or more DC flow pumps inside the tank. In case of a main pump break-down or power failure, having one or two small circulation pumps will keep the aquarium alive. DC water pumps are very efficient and work very well with battery back-ups like the EcoTech Marine or Icecap battery back-up, which can run the pumps for about 48 hours. The Tunze Safety Connector allows you to power your water pump with any 12 to 24-volt battery. You can even use a car or deep-cycle marine battery! Even better, you can swap out a dead battery with a fresh one in seconds. If you have a nano aquarium there’s an easy solution. The Marina battery-powered air pump will provide plenty of water moment and gas exchange with an air stone. It runs on two D batteries, making it easy to power for long periods of time.

types of backup batteries and battery powered air pumps for aquarium emergencies

Return Pump Back-up

The return pump is the main source of water flow through your filtration system. As we’ve discussed, you can plan to get away with a few in-tank powerheads or flow pumps in case of aquarium emergencies, but how easy would it be to replace or repair your main water pump? While the major pump manufacturers strive for reliability, there is always a chance something could cause a failure and usually happens at the worst time too.

A bearing or impeller shaft failure are the main causes of pump problems since they’re the only parts subject to movement and vibration. Even a snail making its way into the pump intake could damage the impeller. There may be a chance it’ll be in stock online or at your LFS and can get it quickly. Though, if you’re running a large heavy-duty pump that isn’t always in stock, you may want to weigh the cost of having a back-up versus waiting a week for a special-order unit to arrive.

Aquarium Heaters

Aquarium heaters are required to stabilize the water temperature and prevent it from dropping due to cold rooms and fluctuations caused by HVAC systems. Many aquarists use two heaters in their tank. The idea is to divide the heating load between two smaller heaters. If one fails, the other heater will keep the water warm enough while you get a replacement. If one heater gets stuck “on” it won’t be powerful enough to over-heat the aquarium. Whether you running one heater or two, it’s a good plan to have a back-up just in case of aquarium temperature emergencies.

Examples of less costly backup equipment in case of aquarium emergencies

Aquarium lighting

Fish won’t suffer if the lighting system goes down, but corals depend on light to survive. LED light fixtures are very dependable and are not prone to failing. If you’re running T-5s, it wouldn’t hurt to have a spare bulb or two just incase one in your fixture goes out. Unfortunately, there are no battery back-ups capable of powering aquarium lighting at the moment, but if you live in an area subject to seasonal hurricanes or serious winter storms, you may already have a back-up generator. If so, you can plan for natural disasters by hooking up the generator with the proper extension cord to safely power your aquarium in case of emergencies.

Is a generator worth it?

If you’ve got a reef aquarium, planted tank or you just love your fish, you may want to consider a small, inexpensive portable generator. For a few hundred dollars you’ll have enough power to run the water pump, heater and lights during a power outage. You’ll even be able to charge your phone! Consider how much time and money you’ve invested in your tank. A back-up generator insures you’ll never have to worry about a power failure again.

Final thoughts

No one likes to focus on what could go wrong but It’s always wise to have a plan! Zoos and public aquariums all have emergency plans in place in case a problem occurs. You can too. Having a battery back-up, an extra water pump or even a battery-powered air pump takes the pressure off should something go wrong. It’s is like an insurance policy for your aquarium!