Can Clownfish Jump Out of The Tank? (With 5 Prevention Tips)

Disclosure: When you purchase something through my affiliate links, I earn a small commission. As an Amazon Associate, I earn from qualifying purchases.

I will never forget the first time I witnessed my clownfish jumping out of his tank. That got me feeling both worried and guilty. Over the years, I have researched that phenomenon a little deeper. I wanted to answer whether or not clownfish typically jump out of their tanks and why that might be happening.

Yes, clownfish can jump out of the tank. That mainly happens when their water conditions aren’t ideal, or in the presence of a predatory fish. Clownfish also jump out as a result of low oxygen concentration or due to an ongoing disease.

As we move forward in this article, I will share a few more reasons why your clownfish tend to jump out of their tank, and what steps you can take to avoid that. I highly suggest that you follow this article to avoid the unpleasant implications of this phenomenon.

Also Read: Clownfish Care Guide

Will Clownfish Jump Out of The Tank?

Yes, clownfish can jump out of the tank. However, do not use that as an excuse to replace them with a superior species. In truth, all fish have the potential to jump regardless of their species. Also, this issue manifests not only in the tank.

You might be tempted to conclude that your clownfish would behave differently if you hadn’t kept them confined to a tank. But that is not true. Clownfish, and fish in general, tend to jump out of tropical and marine water bodies even in the wild.

This is just a natural aspect of fish. However, you should also understand that clownfish typically have a good reason for jumping out of their tank. If you can follow those reasons, you can take countermeasures that will keep them inside the aquarium.

You need to remember that such behavior in the clownfish’s natural habitat isn’t dangerous. That is because the water bodies that fish occupy in the wild are relatively large. Therefore, jumping out of the water for fish usually means falling right back into the same water one or two seconds later.

On the other hand, fish in a domesticated setting are not that fortunate. If your clownfish jump out of its tank, it will probably fall on the table or the floor from where it will suffocate.  

What Science Says

If you think that fish only end up outside their tank by accident, you are about to be surprised. Daphne Soares and Hillary Bierman conducted a study that proved that fish put more thought into this behavior than their owners realize.[1]

Soares started digging into this topic after one of her fish jumped out of its tank into her iced tea. At the time, Soares had a high-speed camera in place. She reviewed the footage and noticed that the fish had backed up to gain additional speed for its jump.

This told her that the jump had been intentional. The fish she was studying at the time was a guppy. However, the research she did showed that many species of fish jump intentionally and purposefully. That may also bring clownfish into the equation.

Soares found that some fish jump because they get their food from the surface. Also, the fish that jumped into her iced tea was looking for a new source of water. This told Soares that fish would jump in search of new water bodies, especially if the environment in their tank was so poor.

For example, Betta fish that live in small puddles encounter challenges in the dry months. That is because their puddles begin to disappear, and the ammonia concentration reaches unacceptable levels. This compels the betta fish to throw themselves out of one water body into another.

This obviously sounds like a risky maneuver. However, betta fish have an organ that allows them to temporarily breathe outside water just in case they fall on dry land. Simply put: it is in the nature of fish to jump. That also includes clownfish, which tend to jump quite frequently.

Why Would Clownfish Jump Out of the Tank?

Learning why your fish might jump out of their tank is necessary to keep them safe. Even though it is typical behavior in nature, it could be dangerous when fish jump in indoor areas. Some of those reasons include the following:

1. Poor Water Conditions

This should be the starting point of your investigation. If your clownfish keep jumping out of their tank, the water conditions might be to blame. Fish have particular requirements. As a fish owner, it is your job to replicate the conditions your fish usually encounter in the wild.

That includes the temperature, pH, and hardness of the water, not to mention the concentration of elements like ammonia.[2] Fish cannot live comfortably in tank water with the wrong parameters. It will either make them sick or kill them outright.

If they become aware of the deterioration of the conditions in their tank, your fish could attempt to escape. They will do so by jumping out of their container. You see this among fish in the wild that will jump out of water bodies that are drying up in the summer. Unfortunately for your tank fish, they don’t have any alternative water bodies nearby to shelter them.

Therefore, try to maintain these parameters within your clownfish tank:

  • Water temperature: 74-79°F
  • pH range: 7.8-8.4

Since the temperature window is narrow, I highly recommend that you use a heater for your tank. Otherwise, there could be wild variations during the winter or summer.

Also, you should ensure that your clownfish have enough room for swimming. Typically you should start with a 20-gallon tank. If there is not enough water volume, your clownfish are likely to get stressed and may attempt to jump out.

2. Poor Oxygenation

Believe it or not, clownfish need oxygen to survive. Unlike humans, they draw their oxygen from the water. It is this absence of water that makes them suffocate on dry land. They cannot draw oxygen directly from the air, no matter how abundant it might be.

If your fish keeps gasping for air near the surface of the tank, you can confidently conclude that the oxygen levels in the tank are lacking. In some scenarios, your fish might simply become lethargic.

But it isn’t unheard of for fish to jump out of a tank in response to the lack of oxygen. That is particularly true for clownfish who typically spend a lot of time at the upper parts of the aquarium. They will spend even more time there when the oxygen levels deteriorate since that is where the maximum oxygenation is.

3. The Presence of Predators

For some clownfish, jumping out of the tank is a defensive strategy. You expect to see such behavior in the wild where predators are waiting around every corner.[3] People think that predators cannot become an issue in a tank because you have complete control over the fish sharing the aquarium.

However, some people choose the wrong tankmates for their clownfish. If the other fish in the aquarium is not only larger but more aggressive, the chances that they might attack your clownfish are high.

If the bullying suffered by your clownfish becomes a consistent occurrence, the creature could seek relief by jumping out of the tank. If it cannot find sanctuary within the tank, it will look for alternatives outside the container.

For that reason, I suggest that you start with mere clownfish at the beginning. Introduce a group of them to a 20-gallon tank and see what happens. If they swim calmly and do not attempt jumping out, you may start adding a few companions gradually. Be patient, and give your clownfish time to adjust to their new tank mates.

Stress can drive clownfish to abandon their tank. Pressure can come from fighting, insufficient meals, poor water conditions, etc. If the fish is forced to endure a continuous barrage of stress, it might eventually choose to take its chances outside the tank.

4. It Could be Infections

Fungal or parasitic infections can dull the senses of your clownfish, compelling them to swim erratically.[4] Sometimes, they will simply skim the surface. In other cases, they might attempt to jump out of the tank. In such cases, they do not necessarily know what they are doing.

Determining whether or not your fish is sick can only be done by observation. If you see white spots or rotted fins, that should raise your suspicions. However, if your fish appear clean and healthy, infection is not likely to be the cause for jumping.

5. Novelty

Some fish might jump out of their tank because they are startled. You see this in fish that are not accustomed to a new tank. This doesn’t happen in every clownfish. It always comes down to the personalities of the individual fish. Some fish are easier to startle than others.

If you’ve just introduced your clownfish to the tank and you see them jumping, give them a while. After a week, they should get accustomed to their new environment. If they continue with the unwanted behavior, perhaps novelty isn’t the issue here. 

6. Inappropriate Lightning

If your fish are struggling to acclimate to their environment in a new tank, bright lighting or sudden flashes of light might cause the sort of fear that startles them, causing them to leap out of their container. Again, this comes down to personality and temperament. Some fish are more accessible to frighten than others.

Either way, you should make the lightning changes gradual. Avoid turning on and off your aquarium all at once. Instead, switch the lights in your room first. After five minutes, once the clownfish gets used to the new environment, you may turn on the direct lights of the aquarium. The opposite is true for turning them off.

7. They do so by Accident

The next time you find your clownfish on the floor, do not automatically conclude that it intentionally jumped out of the aquarium. Some fish do not intend to leave their tank. Instead, it could be that they have stumbled into a situation where they swam too fast.

Then, once they have reached the surface, the momentum carried them right out of the water. Sometimes they flop right back into the water. Other times, they fall outside the tank. Either way, keep in mind that this option could only be concluded by eliminating all other possibilities. 

  • As you can see, your clownfish’s penchant for jumping out of its tank has several potential causes. You are encouraged to investigate until you identify the right source of your clownfish’s behavior. 

How to Prevent Clownfish From Jumping Out of The Tank?

While you cannot always predict the factors that will drive your clownfish to jump out of the tank, you can take steps to keep them from escaping:

1. Use a Lid

This is the most natural and most straightforward solution to your problem. Once you place a lid on your tank, there is nothing your fish can do to escape. If you can help it, avoid covers that limit the amount of light penetrating the water.[5]

Some covers will trap heat while also preventing the exchange of gases between the tank water and the environment. This is why fish owners are encouraged to use mesh covers that will keep the clownfish inside the tank without blocking light or air. 

2. Choose The Tank Mates Wisely

Choose the new additions to your clownfish tank carefully. Look for fish that are neither larger than your clownfish nor aggressive. A cover won’t do you any good if your clownfish are trapped with bullies. 

Also, as mentioned earlier, introduce the new companions gradually. Add a few other species and watch what happens. After a few weeks that you’ve seen everything is okay, you may attempt adding a few others. 

3. Take Care of Their Water Requirements

Keep the parameters of the tank water within the appropriate range. It shouldn’t be too hot or too cold. Pay attention to the pH, salinity, hardness, etc. Don’t give your fish any reason to want to escape the tank.

I also suggest that you replace one-third of your water every week. That would decrease the ammonia levels that naturally arise due to urination. Keep in mind that even though the water appears clean, it could be highly contaminated.

4. Take Advantage of Foliage

If your clownfish have bullies in the tank, add plants and decorations. It will use them to hide.[6] This will enable the clownfish to find a semblance of peace even in tanks that are overrun with violent species.

As a fish owner, you should act to resemble the natural habitat of your fish inside their aquarium. That could be hard to achieve sometimes.

However, introducing vegetation is one of the basic rules each clownfish owner must follow. The most common choice would be anemones, as I have elaborated in this article.

5. Avoid Distractions

Eliminate bright lighting and sources of loud sounds. Remove any element that could startle the clownfish, driving it to act erratically, especially if it is new to the tank. Put the clownfish tank in a quiet location that has little in the way of human traffic.

In situations where your clownfish keeps jumping out of its tank, the countermeasures you take should be determined by the source of your fish’s behavior. If you can figure out why your clownfish keeps jumping out of its tank, it won’t take you long to identify an effective solution.


Yes, clownfish do tend to jump out of their tanks. However, for the most part, there is something you can do to avoid that. The key here is to provide your fish with the ideal conditions and lower their stress. You may do so by adjusting the temperature, pH levels, tank mates, and so on.

I hope my article has answered your question and helped you in avoiding the issue. Either way, I’m sure you’ll learn how to deal with your jumping clownfish with great success. The key here is to keep practicing without giving up.