Betta Fish Stays In The Corner Of The Tank: Reasons & Solutions

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I got a bit worried when my betta fish didn’t seem to leave the corner of the tank for a few days. As time passed, I learned what causes that issue and how to solve it. Luckily, most of the reasons are reversible.

Betta fish tend to stay in the corner of the tank when they are stressed. That usually happens when the water parameters are incorrect, including pH, temperature, hardness, and ammonia. However, some bettas will sit in the corner because the tank is overcrowded or features strong currents.

As we move forward, I will take you step-by-step through the reasons why a betta fish is staying in the corner of the tank and what to do about it. In case your fish is sick, I will share a helpful video that illustrates the most common issues and how to solve them.

Also Read: Stress In Betta Fish

Why Is My Betta Sitting In The Corner?

Betta fish are called Siamese fighting fish because of their aggressive tendencies. They are strong, hardy creatures. But they are not invincible. If they have started hiding in a particular corner, something has gone wrong. Look for signs of the following:

1. The Water Isn’t Suitable For Bettas

Have you checked the conditions in the aquarium? Even the hardiest fish have a limit with regards to the amount of discomfort they can stand.

Is the temperature too high or too low? If the fish is hiding near the heater, the water is probably colder than you realize. If the temperature is too high, the betta will hide in a corner near the top to escape the oxygen deficiency that has manifested below.

If you trust the temperature, look at the pH. Bettas may tolerate a higher or lower pH, but they won’t respond positively to a rapidly changing pH. They demand stability. A pH that swings dramatically attracts stress.

Don’t forget about aquarium cycling.[1] In the absence of proper cycling, the ammonia concentration will spike with annoying frequency. Ammonia is toxic. It poisons fish, burning their gills and leaving red streaks and marks on their bodies.

Like humans, fish respond to stress by withdrawing. A stressed betta will vegetate in a cozy corner of the tank. Depending on the intensity of the ammonia poisoning, the betta may frequent a particular corner because it doesn’t have the strength to move.

The advantage of poor conditions in the tank is that you can identify most of these factors with relative ease. You can test the pH, temperature, and hardness. You can also test the ammonia and nitrite levels in the water. Other factors are more challenging to identify.

2. Your Betta Is New To Its Tank

Because of their violent reputation, people forget that bettas are just as vulnerable to changes in their environment as any other fish. You must acclimate new fish before you add them to your home tank.

This means exposing them to the parameters in the new aquarium before you throw them into the water. But even with proper acclimation, fish in an unfamiliar environment usually present signs of stress.

You see this in goldfish. Because of the number of hours they spend in a small bag during transit and the unfamiliar environment at their destination, they will spend the first few hours or days in hiding.[2]

Bettas are not immune to this sort of stress. They will find a cozy corner and stay there until they grow accustomed to their environment. This behavior is only concerning if it persists for several days, weeks, or even months. Otherwise, the bettas will recover on their own, especially if the tank is well-maintained. 

3. The Tank Is Too Crowded For Bettas

If your tank is too small, the bettas will claim a secure corner in the tank. Crowding tends to attract violence, especially among territorial fish. 

But if your bettas are timid, rather than fighting to claim more territory, they may retreat to a safe, defensible corner. They will stay there until you reduce the number of fish in their environment.

4. There Aren’t Enough Hiding Places

Do you have sufficient hiding spaces in the tank? Some people are convinced that only small, shy, timid fish require hiding places. They expect strong, aggressive fish to get by without them.

While shy fish are more reliant on hiding places, especially in a tank with violent fish, most aquatic creatures will respond negatively to the absence of plants and decorations. Hiding spaces create a sense of security for fish, no matter the size. 

They need to know that they have a sanctuary that can protect them from danger if the need ever arises. The absence of bullies in the tank doesn’t change anything. 

If you don’t have hiding spaces, or if the hiding spaces are insufficient, the resulting stress will force the bettas to find a secure corner. The betta won’t venture out until they feel safe. That won’t happen until you add more hiding spaces. The presence of bullies like cichlids makes things even worse.  

5. The Currents Are Too Strong For Bettas

Is the betta hiding in a random corner, or does it prioritize corners with objects? If the fish is always hiding behind objects in the corner, the current might be too strong. 

Bettas are attractive because they have long, flowing fins. But because of those fins, they struggle to swim in strong currents. If the filter is too powerful, they will find a corner protecting them from the strong current. 

6. Your Betta Caught A Disease

Betta fish are vulnerable to numerous diseases, including dropsy, Columnaris, fin rot, and pop-eye.[3] Diseases and infections make betta fish lethargic. They will settle in any comfortable spot they can find, including the corners of the tank, until they heal.

If the betta in question hasn’t moved in days, you should expect the worst. People think that dead bettas always float to the surface. But this doesn’t happen immediately. In some cases, it may take a few days for the decomposition to reach a point where the fish can float.[4]

Look at the betta’s pupils. Cloudy pupils are a sign of a dead fish. You can confirm your suspicions by pulling the fish out of the tank with a net. If it doesn’t resist, it is dead.

How To Treat A Betta Fish That Stays In The Corner?

If the betta is dead, remove it before it corrupts the water. In case the fish is merely sleeping, activate the lights. If the fish doesn’t respond, prod it gently. If it responds, you can leave it alone. If the betta is neither dead nor sleeping, consider the following remedies:

1. Setting The Right Water Conditions

I highly suggest maintaining the right conditions in the tank. Your bettas have no reason to hide if their parameters are correct. You can also alleviate the stress caused by poor parameters if you improve the conditions in the aquarium. 

That means setting a temperature of 75 to 80 degrees F, a pH of 6.5 and 8.0, and a hardness of 5 to 35 dGH.[5] Also, make sure the ammonia and nitrites are about 0 ppm. The nitrates shouldn’t exceed 20 ppm.

To measure the pH, ammonia, nitrates, and nitrites, I use the API Water Test Kit (link to Amazon). That is absolutely my favorite since it lasts for about eight hundred measures, making it highly cost-effective.

I also recommend getting the Seachem Prime Fresh and Saltwater Conditioner (link to Amazon). That product will help you prevent ammonia spikes, which can negatively impact your betta’s breathing.

It is also essential to keep an eye on the lighting. Harsh lighting produces stress, and stressed bettas will hide in the corners if they don’t have plants and decorations. 

2. Dealing With Ammonia

Many aquarists will encourage you to keep water conditioners on hand, and for a good reason. In an emergency, one where ammonia poisoning has pushed your bettas to the brink of death, you can use water conditioners to alleviate their distress within minutes.

But water conditioners cannot protect your fish from harm if the tank is not fully cycled. An uncycled tank is prone to rapid and frequent spikes in ammonia. 

If you cycled your tank to completion, but the ammonia keeps spiking, you probably undid your hard work by either replacing the filter media or washing it with chlorinated water.

Fortunately, you can remedy the issue by adding filter media from an established tank. Don’t forget to carry out regular water changes. As a rule of thumb, I replace 15 to 20 percent of the water weekly.

Dirty water makes fish sick, which is why filters are so important. Though, you have to pay close attention to the current they generate. It shouldn’t be so strong that it stresses the bettas.

These factors support each other. You must cycle a tank to completion, but it is also vital to carry out regular water changes. It is just as important to treat new water with water conditioners. You can kill your bettas by eliminating just one of these factors.

3. Adding A Few Hiding Spaces

Because bettas don’t eat plants, you can add natural foliage to the tank. Add floating plants that act as a water flow break. Invest in decorations with smooth edges. Sharp edges will tear the fragile fins and tails of your bettas.

When I had trouble with my betta fish, I got him the PINVNBY Coral Aquarium Decoration (link to Amazon). Once I introduced this beautiful craft, my betta couldn’t leave it. Besides building its confidence, this ornament is absolutely stunning.

4. Fixing An Overcrowded Tank

Bettas require at least five gallons of water. If you have the means, get the largest tank possible. If you can’t afford to buy a large tank, limit the number of bettas in the tank.

For your convenience, here is an article where I discussed how many betta fish should be kept together. In there, I made a distinction between male bettas and females. Naturally, the male ones require larger tanks.

If you feel that your tank is too crowded, remove some of the decorations or plants. But if you are considering a new tank, I personally recommend the Tetra Aquarium 20-Gallon Fish Tank Kit (link to Amazon).

To eliminate the conflict in the aquarium, you must keep the male bettas alone. It isn’t enough to pair the bettas with suitable tankmates like tetras and large ghost shrimp.[6]

You can create chaos by keeping multiple male bettas in the same tank. The resulting conflict will force the weaker bettas to hide in the corners.

5. Saving A Sick Betta Fish

If your betta fish stays in the corner, it could be sick. In this case, the fish will also present signs of illness, such as lethargy, labored breathing, color changes, etc.

The best way to identify the disease is by observation. Then, you can compare your fish’s appearance to other sick fish. For your convenience, here is an excellent YouTube video that discusses the most common diseases in betta fish and how to treat them:

Are Betta Fish Usually Active?

Healthy bettas are usually active. They spend their days exploring the various nooks and crannies of the aquarium. They do not have a reputation for lying still or hiding in the corners. If that happens, the fish is probably suffering from an underlying condition.

As mentioned above, bettas that stay in the corner and become less active require your attention. The first way of action would be testing the water parameters, including the temperature, pH, and ammonia.

Also Read: Why Does My Betta Fish Stay In One Spot?

Is It Normal For Betta Fish To Hide?

Under normal circumstances, it is unusual for bettas to hide. They are not considered a shy species. However, certain factors in the tank can cause betta fish to hide. That includes bully tankmates and inappropriate water conditions. In some cases, the fish hides because it sleeps.

If the bettas in question refuse to emerge, even when you add food to the tank, something has gone wrong. A hiding betta should also concern you if it looks unwell. For instance, if it has torn fins, bruises, streaks, bloating, etc.


Betta fish usually sit at the corner of the tank due to stress. Nearly all kinds of stress, such as overstocking and poor water conditions, can cause the fish to hide. Bettas can also become anxious and stressed if they are new to the tank. 

The first step in resolving this problem is to check the tank for ammonia, nitrite, and nitrate. I also suggest checking the water temperature and hardness. If everything is correct, make sure your tank isn’t overcrowded or features some strong currents.