Betta Stress Stripes: Everything You Need to Know

Last Updated on March 1, 2021

Bettas have naturally bright colors that are eye-catching and impossible to ignore. This breed has become one of the most popular fish to keep as house pets.

With regularly looking at their beautiful colors, have you ever noticed dark, vertical stripes on their body? ​​​​​​​

If you do, then that probably means they have betta stress stripes.

What are betta stress stripes?

In a nutshell, betta stress stripes appear when there are sudden changes in your fish tank that do not suit their specific needs. Your betta may lose its bright colors as a reaction to different stressors. Their bright colors may change, and you might observe them acting unusually.

The appearance of stress stripes can lead to a couple of ailments like dropsy and popeye.

Betta stress stripes are usually the first sign that something is wrong with your betta and your fish tank.

These stripes are usually horizontal lines that run from your betta’s body and are more apparent on female bettas than males.

In this article, we’ll talk about how it happens and what you can do to lessen the risks of your beloved betta getting stress stripes.

Factors why betta stress stripes appear

Betta fish stress stripes are a sign of poor water quality and a sign that the fish is experiencing psychological stress. Check out some other factors why stress stripes appear on your betta.

Small tank


Transferring your new betta from the pet store to a permanent aquarium is already stressful for them and might take weeks of getting used to – what more if you transfer them into a small tank? The average tank size for your betta should not be smaller than 5 gallons. Since bettas love to explore and goof around, having a small tank might make their activities impossible to do which will only increase their stress level.

Stripes appear whenever your betta is stressed out and only having a small space to roam around will only worsen their anxiety. Knowing this, it is good to consider the size of your tank before taking your beloved bettas home.


Similar to having a small tank, if your betta’s tank is overcrowded, then the living condition of your fish will be very poor – if they survive in that environment. If you are not sure about how many fish you should place inside a tank, one of the general rules is that a one-inch fish should be equal to one gallon of water.

However, although this is the general rule, it is still best to research thoroughly the recommended tank size for the number of fish you are planning to take care of.

Related: Betta Fish Care in a Nutshell

Poor water condition

Maintaining a proper water condition for your fish is as important as providing them with the best environment they could live in. Another thing to remember as a betta owner is to make sure that the pH and water temperature of your tank is just right for your little friend to avoid the risk of having harmful bacteria, parasites, and algae.

Sudden water condition changes

A sudden change in your tank’s water condition could cause shock and stress to your betta. You may relate these changes to water levels, introducing new products to your tanks such as decorations, or spraying chemicals that might be harmful to your fish.

It is important to always check your water condition and see if the products you are using are safe for your betta.

Lack of hiding place

Bettas sure do love to hide! There are many toys available specifically to serve as their hideouts such as logs, shells, and caves. Taking away one thing your betta enjoys doing will surely cause them sadness and anxiety.


Illnesses and diseases are another cause of stress for your betta, which could be parasitical, bacterial, or fungal. If left untreated, your betta’s health will often become fatal, so it is important to check on their health from time to time.

Aggressive tankmates

If you have other fishes in your tank besides your betta, it is good to examine if they are compatible with each other. Your betta can develop stress because of other fishes without showing aggression and outward signs. Examining your betta’s color and change in behavior when introduced to other species is a good way to notice if they are compatible with their tank mates or not. If you notice this, consider if it is best to keep them inside a tank with other fishes or if it is best to just put them in their aquarium.

Symptoms of betta stress stripes

How do you know if your betta is experiencing stress? This may vary from one fish to another, but here are some common symptoms that your betta might experience when under stress.


Although bettas love to hide, stress could also cause your fish to hide more than usual. If you notice your betta spending more time hiding rather than swimming around, then it is most likely that they are experiencing stress and anxiety.

Lack of appetite

Another symptom to look for is if your betta loses its appetite. If they eat less or stop eating at all, then you’ll know that something is wrong with your betta.

However, stress might not only be the factor for lack of appetite. Other things to consider are that constipation, illness, or even depression.

Related: How Often Do Betta Fishes Poop?


Did you know that stress can cause your betta to become sick? Researchers believe that stress can increase the risk of developing diseases or illnesses. When you have a stressed betta, their immune system is weak, which makes them more at risk of getting infected.

If you notice your betta might be sick, it is important to look for the cause of their stress, such as a poor environment and having tank mates.

Skittish behavior

Betta’s moving and swimming around quickly can be typical behavior. However, if you notice your bettas are darting around constantly or are swimming skittishly, it is most likely that they fear something such as their tank mates.

Behaviors to look out for when your bettas are swimming erratically are crashing and rubbing into rocks and gravel and even clamping their fins.

Changes in color

A color change could show that your beloved friend is stressed out. From its lively self, your betta might change its color into a duller and paler shade. Aside from becoming paler, stress stripes will also appear on its skin, which could also show depression.

What can you do to prevent


Now that you already know what causes your betta’s stress, how and what can you do to prevent it from worsening? Identifying first what causes the stress is important to make it easier for you to help your friend.

Here are some common ways you can do to prevent your betta from stressing out.

Change water frequently

Changing your tank’s water might be stressful for your betta, but not as stressful as not changing the dirty water. Typically, it is good to change your tank’s water once every week or two weeks depending on its size. Cleaning the water reduces the amount of ammonia and nitrates, making it safer and healthier for your betta.

Use a stronger filter

Having a good and sustainable filter alongside the cleanliness of your tank’s water can help reduce your betta’s stress. Filter helps your water tank clean whenever you are not around it that is why it is good to invest in a strong filter to keep your bettas stress-free.

Just remember to not buy a filter that produces current or else your betta might go from a 0 stress level to a 10 instantly.

Remove bully fish

Bullies are never good news. If you notice that your betta or the other fish is becoming aggressive with one another, the best way to intervene is to separate them and transfer the other to a different tank.

Set up hiding spots

What is the best way to prevent someone from stress other than giving them the thing they love the most? In your betta’s case, providing them with hiding spaces can help reduce their stress and make them feel more relaxed.

By giving them enough hiding places, your fish will have a space to rest without the fear of being attacked by others.

Give them high-quality food

Giving your betta high-quality food can help boost their immune system and their health. If you are giving them low-quality food, then start reconsidering their diet.

Having a low immune system could stress your fish out and make them more prone to infections and diseases. When choosing good quality food for them, feed your betta with high-quality pellets and live and frozen food.

Provide a bigger tank

As mentioned earlier, your betta needs at least 5 gallons of tank space to be happy and free from stress. You may have seen or heard that bettas can survive with only a 2.5-gallon tank size, but there is a big difference between surviving and happily living.

If you want your little friend to live happily away from stress, you might provide them with at least a 5-gallon tank.


Treating your betta with the utmost care is the best way to prevent them from stress. Providing a safe environment for them to swim around is the greatest gift you can give your tiny companion.

Although stress sometimes is unavoidable, knowing what causes it and how to prevent it is an essential tool you can use whenever you notice your betta needs your help.

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