Emergency Protocols for Home Aquariums

by | Apr 15, 2008 | 0 comments

Many people speak of the importance of being prepared for any “unforeseen situations” with their aquariums. This is actually better stated as preparing for “unwelcome situations” – as all of these situations can be planned for because you should be aware they could happen. Truly unforeseen situations only occur to unprepared people that lack an overall knowledge of aquariums. For instance, it might be unforeseen by a beginning aquarist that a heater that sticks in the on position will raise the water temperature and possibly kill their fish. For an experienced aquarist, the potential for this problem is known, and it then becomes an unwelcome situation if it occurs. With the complexity of aquariums growing, (especially reef tanks) the issue of properly handling emergencies becomes of paramount importance. You should compare aquarium emergency pre-planning to having insurance, but unlike home and auto insurance, nobody is going to mandate aquarium preparedness for you.

All aquarists should be reasonably prepared to preserve the lives of the organisms in their care should some disaster strike. The two points at the heart of this issue is the personal responsibility for the animals in the aquarist’s care, and the animal’s replacement cost should anything happen to them. To be perfectly frank, aquarists do need to perform a cost-benefit analysis on the potential emergency protocols that they intend to implement. Having no plan is of course the least expensive option – but obviously offers no protection at all. On the other hand, having complete equipment redundancy with automatic back-up power supplies could cost many times more than the animals themselves. Each aquarist needs to determine the risk level that they feel comfortable with. Remember though that you are dealing with the lives of animals that you are solely responsible for, so the effort given towards emergency planning needs to be done with that in mind, not just the replacement cost of the animals.

Just how widespread is the issue of aquarium emergencies? Obviously, we all know the potential is there to lose animals due to emergencies, but how common of a problem is it? In one online poll, 38 percent of a group of marine aquarists reported having lost animals due to a power failure. This is significant in that many more aquarists had experienced problems, but were able to manage the issue without loss of animals. It seems then that it is safe to assume that if you stay active in the aquarium hobby long enough, you will experience an emergency with your aquarium at some point.


Types of emergencies

Power outages are perhaps the most commonly experienced aquarium emergency. Most marine aquariums develop low dissolved oxygen problems within a few hours of the power going out. During the winter, loss of power may also cause problems with low water temperatures. There are a variety of resources discussed later that mitigate the problems caused by power disruptions.

Fires can be devastating to aquariums. Obviously, aquariums will be damaged if exposed directly to the heat or flames from a fire, but even a small kitchen fire can kill aquarium inhabitants due to exposure to smoke. Assuming there is no immediate threat to humans, emergency procedures to prevent smoke damage include temporarily isolating the aquarium by turning off filters and air pumps and sealing the entire aquarium in plastic sheeting. Smoke can further be excluded by then setting up a large air pump or blower outside the smoke-filled area to blow fresh air into the “isolation tent” made of plastic sheeting.


A natural gas genset used by a public aquarium for 25 years.

Equipment failure is also a common causes of aquarium emergencies. A stuck float switch or check valve can disable an aquarium’s life support system in a matter of seconds. A seized circulating pump may cut off all water flow to an aquarium. Heaters that stick on or off will cause disruptions in the aquarium’s water temperature. Catastrophic water loss through a plumbing failure or a tank leak can be devastating to the animals as well as causing water damage to the home. With very large glass aquariums, especially homemade ones, the question is usually not “will the tank leak?” but “when will it leak?”

Averting the Most Common Disaster of All!

The most important device to reduce animal loss in an aquarium is a quarantine tank and a comprehensive system to quarantine all new arrivals. It truly is a disaster to introduce a new specimen into your aquarium and bring in a disease at the same time.

Any natural disaster that affects a person’s home will have an impact on their aquariums. One story goes that Indo-Pacific lionfish having found a new home in the Atlantic Ocean could have possibly arisen from lionfish swept from their aquariums in Miami out into Biscayne Bay by hurricane Andrew.

There is one category of emergency that doesn’t quite fit with the topic of this article – when a human health emergency is caused by an aquarium animal. These are cases where the aquarium itself is in no jeopardy, but the aquarist has been injured by one of their animals. Know the relative health risks of all of your aquarium animals and avoid any species that can cause serious human health problems, especially in homes with children.

The life support criteria that must be managed during an emergency include dissolved gasses (primarily oxygen), light (for corals), temperature, and in long-term emergencies, nitrogenous wastes. There are a variety of methods available to help an aquarist maintain life support systems. Some are just temporary or partial fixes, and the cost can vary greatly between methods. A lesson in pre-planning can be taken from public aquariums that certainly have a need for emergency life support systems for their valuable aquatic exhibits. The Association of Zoos and Aquariums, a member organization that accredits many of these facilities has standards for their members that addresses this issue. First, all AZA members must have written emergency protocols, and then use them to conduct periodic drills. AZA member institutions must also have warning systems such as fire alarms and emergency lighting in place to alert for a failure in any of their aquatic life support systems. In addition, the AZA requires that “emergency backup systems must be available” for the life support systems. Many public aquariums use large auxiliary generators with automatic transfer switches to serve this purpose. What does all this mean for home aquarists? Simply put, anything that is such a high priority with professional aquarists must be considered important for serious home aquarists as well.


Possible solutions

Uninterruptible Power Supply (UPS)

Commonly used to maintain computer operations during short term power disruptions, a UPS system’s greatest attribute is that it automatically switches on when the power goes out. Remember that by design, a UPS unit only needs to power a computer long enough for the user to save their work and shut the computer down. For that reason, the battery bank in a UPS may not have much capacity. Except for the smallest aquariums, a UPS device should really only be relied upon to run a small pump or to maintain power to any computer controls on the aquarium that might lose their memory during a power outage.

Power inverter

Having a power inverter can be very helpful in some instances. These devices convert 12 volt direct current to 115 volt alternating current that can then be used to power aquarium equipment. Like generators, these devices have power ratings for peak and continuous usage, so be sure that your expected total wattage will be less than 80% of the converter’s continuous rating.

A 150 watt inverter may cost $20 to $30 and can run basic life support for small to medium aquariums. For $10 you should be able to find a 40 watt inverter that can power a small air pump and maybe even a small circulating pump. It is often recommended not use an inverter rated higher than 300 watts if it plugs into a cigarette lighter socket as it may cause the vehicle’s fuse to blow. Inverters with a capacity of greater than 1000 watts may require high output alternator and banked batteries (as might be found in a recreational vehicle). Some electronic devices will only work with inverters that produce what is termed “true sine wave” electricity, so check with the manufacturer for the specific needs of your equipment.


An automatic generator transfer switch at a public aquarium.


The primary emergency electrical system for most homes and businesses is an electrical generator that runs on fuel (gasoline, diesel or natural gas). These devices range in size from tiny 600 watt portable units to whole-building generators with automatic transfer switches. When sizing a generator for your needs remember that pumps and chillers all require a peak starting power greater than their rated wattage while running. Advice from an electrician should be sought when planning a power generation system using large generators.

SCUBA tank

Enterprising aquarists who are also divers may want to rig a device that will aerate their aquariums from a SCUBA cylinder. Using the first stage from an old regulator, the LP hose can be attached to a needle valve that can handle the rated pressure of around 150 psi. From the needle valve, a standard aquarium airline runs into the tank ending with an airstone. Simply cracking open the SCUBA tank valve will aerate the aquarium for at least two hours. Periodically closing the valve can extend the life of the air in the cylinder ten-fold. Anyone with access to a medical or welding oxygen cylinder can rig a similar, but much more effective aeration system.


Emergency cooling methods

Adding ice to an aquarium is one possible solution to high water temperatures resulting from a chiller failure. In marine aquariums the ice must be isolated from the seawater either by a plastic bag, or by freezing water beforehand in two-liter plastic soda bottles. The most important question is, “How much ice will be needed?” The best way to answer this question is to run a quantitative test before you experience an actual failure of the life support system. Prepare a series of ice blocks or frozen two liter bottles of water. Then, disconnect the chiller or turn off the air conditioning and add measured amounts of ice to the aquarium and record the results. As long as some ice remains, do not add more. As the ice melts fully in each container, remove it and replace it with another frozen one. Monitor the water temperature during this process, adding more ice if the temperature rises and removing some if the temperature drops too far. Run this test for 4 to 6 hours and then calculate the amount of ice it took to maintain a stable temperature and divide by the numbers of hours. This number will be the amount of ice you will need to keep the aquarium at a proper operating temperature for the period of the expected equipment failure or power outage. To put this in perspective, in one actual test 4 pounds of ice was found to hold a 30 gallon aquarium at its set temperature (25 degrees below ambient) for three hours. It took 8 pounds of ice to hold a 120 gallon aquarium 25 degrees below ambient for three hours. A 500-gallon concrete tank was held at 15 degrees below ambient for 2 hours with 22 pounds of ice (Hemdal 2006).

Another method of emergency cooling that works especially well if the temperature does not need to be lowered too much is to use cool tap water running through 50 to 100 feet of vinyl tubing immersed in the aquarium or its sump, with the hose output running to a drain. Turning the tap water flow rate up or down will serve as a rough way to adjust the aquarium’s water temperature – a type of cooling coil.


Maintaining hydration

In cases where the aquarium has leaked or the plumbing has failed, the animals may be exposed to the air and will soon die if not rescued. For fish and macro-invertebrates, the solution will be to move them to a container housing enough seawater to keep them alive until the situation can be resolved. This may be something as simple as temporarily moving these animals to the aquarium’s sump.

What about an aquarium filled with corals and live rock? One often overlooked answer to this problem lies in a roll of paper towels. Corals can survive for varying lengths of time out of water if kept from drying out completely. In fact, some live corals are routinely shipped “damp” wrapped in plastic sheeting or even damp newspaper. Soaking paper towels in seawater and then draping the towels over corals and live rock will keep them alive for anywhere from four to perhaps as long as 36 hours. Covering the top of the aquarium with plastic sheeting and/or ladling fresh seawater on the paper covered corals can extend the time they can survive out of water.


Chemical additives

There are cases where basic life support systems can be maintained, but some water quality parameters begin to fail anyway. For example, in a long-term power outage, fish life may be saved by some device, but the corals begin to die due to lack of light or some other factor. In these cases, nitrogenous wastes (ammonia) must be managed. There are a few ammonia neutralizing chemicals on the market, and should be a part of every aquarists “medicine chest”. Some aquarists have experimented with using hydrogen peroxide as a supplemental source of oxygen, but as this compound is so reactive, it is difficult, if not impossible to dose correctly during an emergency.

Emergency Procedure Safety

Aquarists are cautioned that some emergency protocols can create a risk to health and property. Remember that these situations often mix electricity, internal combustion engines and water – all during potential disaster conditions such as storms and floods. The best way to avoid problems is to fully understand the operation of every piece of safety equipment before you need to use them. Always follow the manufacturer’s instructions and never use a device outside its operational parameters.


When to initiate emergency procedures

Its common practice for aquarists to start up an emergency life support system immediately after the emergency begins. The power goes out, and the natural reaction is to start up the battery back-up system or the generator right away. There are a few cases though where it is best to wait. For example, batteries have a finite amount of energy available to run the life support system. Once that reserve is exhausted, they stop. Think of an aquarium that is operating normally and has a dissolved oxygen saturation level of 8 ppm. The power goes out and the dissolved oxygen level hold steady for a time and then begins to drop. If you start the battery back-up right away, some of its energy will be wasted holding the dissolved oxygen at, or slightly above the saturation level. On the other hand, the animals can survive oxygen concentrations down to some point below that of saturation. It you wait to start the battery back-up until the dissolved oxygen levels drop a bit, then more of its energy will go to maintaining an acceptable dissolved oxygen level. How long to wait is a matter of good estimating. Without a dissolved oxygen test kit, it may be a bit of a guess, although you can certainly observe the fish’s respiration rates, and don’t begin emergency aeration until a slight rise in their breathing rate is noted. Another application of this idea is when using ice or other finite water cooling method. Delaying the use of ice until needed will extend the length of time that the aquarium’s water temperature is kept within a range that can be survived by the animals. The associated graph attempts to show this pictorially. Animal loss occurs when any of the lines crosses the red threshold. Notice that by initiating the emergency procedures only when absolutely necessary, the animals can be kept alive a bit longer.


When to abandon rescue attempts

There are going to be some unfixable situations, where nothing you can do will help your animals. Examples include; the house holding the aquarium sustains structural damage, the power remains out too long or the floodwaters rise to the tank level. In these cases, it may be best to give up trying to maintain life support systems and determine if there is any way to move animals to a safer place. Paramount to all this is you must discontinue any attempts at emergency aid for your aquarium if there is any risk to human safety. An example of this would be staying with your aquarium during a wildfire, or not evacuating your home after damage from an earthquake. While this may seem like obvious common sense, in the heat of the moment people sometimes make poor decisions.

The reaction of the staff of the Aquarium of the Americas in the wake of hurricane Katrina is a good example of proper handling of aquariums after a massive natural disaster that could not prevent animal loss. According to published reports, the Aquarium of the Americas lost many of their 10,000 specimens when their emergency generators failed due to flooding. Aquarium staff that remained behind managed to save certain high value or air breathing animals by moving them out of the facility to safety. In most opinions, there was nothing else that could have been done in this case – emergency generators are typically designed to keep animals alive for the short term, not during months of rebuilding following a disaster of this magnitude.

The Aftermath: Added Insurance

When the emergency is over, regardless of the success you’ve had in saving the animals, there may be the additional step of contacting your insurance company to file a claim:

  1. Always speak with your agent beforehand so that you know what is covered and what isn’t (live animals are rarely covered, and you may need a special rider to cover water damage from an aquarium).
  2. Prepare an inventory of your aquarium equipment, both as a list and in pictures or video. Receipts are also helpful. Needless to say, don’t store these records in the same area where the inventoried items are!
  3. Document the loss in the same manner, especially if you took steps to reduce the claim (making repairs to broken windows, renting a generator etc.)
  4. Contact your insurance company as soon as possible following the loss.



Aquarists should have a written protocol for household members to use to take care of the aquarium in their absence. It does no good to build redundant systems, have power back-ups at the ready and then be out of town when an emergency arises.

Preparing for aquarium emergencies is a bit like listening to a sales pitch for life insurance; it is probably a good idea, but nobody really enjoys the process. While this article cannot solve every aquarium emergency, it hopefully gives some ideas that can be implemented with little cost which may pay big dividends in saving the lives of aquarium animals.



  1. Hemdal, J.F. 2006. Advanced Marine Aquarium Techniques. 352pp. TFH publications, neptune City, New Jersey
  • Jay Hemdal

    Jay Hemdal has kept aquarium fish since he was four. He set up his first marine aquarium in 1968 when he was nine years old. He later worked part time for many years at various local retail pet stores and fish wholesale companies while he was living at home and then during college. After graduating from college with a degree in aquatic biology, he managed the aquarium department of a large retail pet store for five years until 1985, when he was hired as an aquarist/diver (and later department manager) for a large public aquarium. In 1989, he accepted the position of curator of fishes and invertebrates for another public aquarium, where he remains today. Jay has written over 200 articles and papers as well as seven books since 1981.


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