What Causes Betta Stress Stripes? (& Prevention Guide)

Betta fish are beautiful to look at largely because of their big fins and bright colors. 

But when those colors dim and stripes start showing up, it’s a bit alarming. 

When our fish did this, my son panicked. We had to research the causes of betta stress stripes and how we could help. 

Betta stress stripes are a naturally occurring reaction to the changes in the environment, such as new homes, fish, decor, or problems with the tank itself. Stressed bettas lose their bright colors, and stripes become more vivid on their bodies.

betta stress stripes ATF

What Are Betta Stress Stripes?

Have you ever read a book, watched a TV show, or seen a person panic? They often “go pale,” right? 

A similar thing happens to our bettas when they get stressed. 

In a stressful environment, your betta will “pale” as well. 

The normally bright hues on the colorful fish will dim and fade. The stripes they have on their bodies become more clear as a result. 

These dark and light stripes aren’t always visible. But on a stressed fish, they’re quite noticeable! 

These stress stripes show up as horizontal lines (opposite of zebra stripes). 

The thickness of the lines depends on the type of betta fish and the individual fish in question. 

Stress stripes are an instinctive way your betta communicates with other tropical fish. Bettas know what these lines mean and can take action if needed. 

Other fish will know something’s up in the wild when they see the horizontal stripes. 

Fear stripes are more intense versions of stress stripes. This is when they’re panicked from extreme stress. 

Females are more likely to have this issue than their more aggressive male counterparts. 

Males can have stress lines, but it’s not as common. More often, they show stress by getting lighter in hue and being more active (think spastic) in the tank. 

Note: Breeding stripes on female bettas are also possible. These run vertically (up and down like a zebra). 

Whatever the specific look, you need to recognize when this happens and take action to help your betta out. 

stress stripes vs breeding stripes data

8 Causes Of Betta Stress Stripes

These 8 items are the main causes of stress in betta fish, which is why they have stress stripes. 

Other signs of stress include: 

  • Hiding
  • Lack of appetite
  • Quick, rapid movements in response to sound and movement

Look through these to help determine what may be causing your betta’s stripes. 

#1 New Home

The bulk of stress stripe causes is related to environmental problems. 

The trauma of being moved to a new tank or aquarium is top of this list. 

There isn’t much to do to fix this stress on your fish. 

Even if you do everything right, your betta will probably be stressed out. 

However, there are a couple of ways to limit the amount of stress your betta is under: 

  • Make sure the water in the tank is at the correct temperature. 
  • Keep other fish away from the betta as it gets used to the tank (use a divider if needed). 
  • Let the betta sit in its original carrying package (a plastic bag or cup, typically) for 15 minutes. This lets the water gradually adjust to the next temperature. 
  • Keep the lights low, keep movement outside the tank down to a minimum, and don’t tap on the glass. 

#2 Changes To Tank

Similarly, any changes to the existing aquarium may stress it out. 

This may happen from something as simple as a 20-25% water change (which we recommend) to putting a new plant in the aquarium. 

Any changes may cause stress in your fish which may cause these stripes to show. 

Limit their stress by picking only the best and proper plants/decor for the tank. And go out of your way to disturb the fish as little as possible. 

#3 Poor Water Quality

Water problems, such as when the needed parameters are off, are one of the sneakiest problems for betta fish.

Incorrect temperature, nitrates, oxygenation, or any of the other elements cause several issues in bettas. And they show up in different ways. 

Sometimes, your fish won’t even show signs of a struggle until they, sadly, pass away. 

But more often, they’ll start to show any number of stressed behaviors, including stress stripes. 

The water is one of the first things I check with my betta when I see stress stripes. 

This assumes I can’t pinpoint a change in the tank or moving tanks as the cause. 

Read more on what water for betta fish should be like in this article.

#4 Overcrowded Tanks

Bettas need space! They can get along with other fish as long as it’s a compatible species. 

But they still need the space to swim around and not be overwhelmed by the others in the tank. 

Bettas do well in a 10-gallon tank with about 4-5 fish. This is, of course, if those fish or aquatic species are well-suited companions. 

Check out our complete list of betta fish tank mates at the link. 

Note: Don’t keep male bettas together. They fight and kill each other. 

Also, don’t keep male with female bettas. They’ll breed and produce a LOT of betta fry spawn.

dont keep male betta fish together data

#5 Other Aggressive Species

Some species tend to be aggressive. And even if the species is usually fine with bettas, some personalities may come off as bullies. 

Bettas are usually pretty tough. They are known as Siamese Fighting Fish and Japanese Fighting Fish, after all!  

But it’s not true 100% of the time. If you notice a fish bullying your betta, this stress may cause the stress stripes to appear. 

Common fish bullying behavior includes: 

  • Nipping at them
  • Chasing them around the tank
  • Preventing them from eating

#6 Too Much Noise, Movement, Or Light

As beautiful as they are, bettas don’t like it when there is a ton of light. 

They also really don’t like it when there is a lot of movement and noise right by their tank. 

This triggers their flight and survival instincts. As fun as it may be for a young person to tap on a tank and watch the betta swim around quickly, this isn’t a good idea. 

In some cases, too much light, motion, and noise may even cause a betta fish to have a seizure! Read more about this in our article at the link. 

#7 Not Enough Space  

One of the most frustrating mistakes we see new betta owners make here at Betta Fish Bay is the aquarium’s size. 

Pet stores wrongly sell tanks “made for betta fish,” which are just too small. 

A too-small fish tank causes many problems, and one of them is stress.

We recommend, in our betta fish tank setup guide, you get a 10-gallon horizontal tank. Five gallons is the minimum size. 

This is not just our experience talking. This is the vet-recommended size too. 

#8 Illness

When your betta is sick, these stripes may show up too. 

The stripes will be just one of the symptoms, so watch for other signs too. 

This may include: 

  • Lack of appetite
  • Sluggishness (bad for such active fish)
  • Gasping for air at the top of the tank
  • Visible injury
  • Frayed and damaged fins
  • White spots on its body and fins
  • Trouble swimming straight 

If you see several of these signs, your betta is probably ill. 

We recommend contacting a vet for their advice. They may prescribe a simple medication or ask you to watch for other signs. 

Sickness comes from many causes, including bacterial, viral, fungal, and parasitical infections. 

A vet is needed to help them, so don’t be afraid to call. 

5 Ways To Prevent Stress In Your Betta Fish

ways to prevent stress header

While betta stress stripes aren’t a cause of danger in and of themselves, they do indicate stress in your pet. Long-term stress is dangerous for the health of your betta. 

Check out these 5 easy ways to prevent or limit stress on your betta fish and prevent stress stripes in many instances. 

#1 Feed It Quality Food

Betta fish are pretty hardy when it comes to food. 

They don’t need much to survive and can technically live off pretty much any food. 

But we don’t want them to survive; we want them to thrive! 

Poor diet adds stress to them. Even if they don’t show it all the time, poor nutrition sets them up for an increased stress response when the items above happen. 

Give them quality betta fish food like specifically-made betta pellets, and they’ll be less stressed overall. 

Our top pick for betta food is the New Life Spectrum Pellets on Amazon. 

They’re affordable but packed with quality ingredients and needed nutrients. 

#2 Put The Tank In A Safe Place

Yes, we want to see our betta pets. 

But they don’t need to be in a place where people, dogs, kids, vacuums, TVs, and all other kinds of things are making sounds (betta fish can hear) and moving all of the time! 

Keep the tank either in your living room or bedroom, but keep it against the wall and away from the entrances and well-traveled areas of the room. 

Also, don’t put it by a window. 

For one, the windows may make the water too cold in the winter. 

For another, natural light may cause big problems. 

It’ll heat up the water quite a bit. And it’ll cause algae blooms. 

This may, in turn, cause infection and sickness. 

#3 Treat Illnesses / Call A Vet

I mentioned this before, but it bears mentioning again. 

If your betta is sick, waiting for it to heal will NOT cause the stress level to go down. 

You’re taking a risk on your betta’s life. 

At the very least, you need to call your vet for specific advice. They may advise you to wait. 

But they may also advise you to add a specific medication twice a day. 

There’s no way of knowing without getting help. 

#4 Monitor The Water Conditions

Maintaining proper water parameters is essential in keeping your bettas healthy and unstressed. 

Ideal Water Parameters for a Betta Fish Tank Include the following:

  • Temperature: 78-80° degrees Fahrenheit (25.5-27° C)
  • pH: 6.5-7.5
  • Ammonia and Nitrite: 0 ppm
  • Nitrate: < 40 ppm
  • gH: 3-4 dGH (50-66.7 ppm)
  • kH: 3-5 dKH (53.6-89.4 ppm)
  • Minimum Tank Size: 5 Gallons

Check the water temperature at least once per day; more is better. 

For the other elements, check them at least once per month. 

But if you notice odd behavior or stress in your fish, check the water right then. 

If there is a problem, you’ll need to check it daily or every two days until it’s fixed. 

#5 Provide Engaging Tank Decor

Bettas don’t just need plants and decorations as something to play on and swim around. 

They need them as places to hide and rest. 

Without them, your fish won’t feel safe. An unsafe fish is a stressed fish. 

Examples of safe plants include: 

  • Anubias
  • Java fern
  • Marimo moss ball
  • Water sprite
  • Betta bulb

Other examples of good decorations also include: 

  • Caves
  • Floating logs
  • Castles
  • Rocks

Warning! Don’t use decorations made of metal or not rated for submersion in water. Rust will come off the metal and make your fish sick. 

If an object isn’t rated for water, some paint or other chemicals may seep into the water. 

Get Those Stripes Away!

No betta owner wants their fish to be so stressed they enter a fight or flight response. 

By properly taking care of the tank, we avoid many problems and help our fish live long and happy lives. 

Share this with your other betta owner friends, and let’s help our fish stay happy and relaxed!

Frequently Asked Questions

What Are Female Betta Fish Breeding Stripes?

Female betta fish communicate they’re ready to breed by showing stripes. These are vertical stripes instead of horizontal ones. For more information on breeding, check out our betta fish breeding guide. 

Do Betta Stress Stripes Go Away?

Betta stress stripes don’t stick around when the stressful issues are fixed. They go away, though it may take a few days to a few weeks from when you fixed the environmental problem. 

How Long Does Fish Stress Last?

If fish only have a 5-minute memory, won’t they just let go of their stress when the problem is fixed?

Fish take between 4-6 weeks to release their stress fully. Stress isn’t a memory or something held in their minds. Stress is a physiological response to something. As such, it takes time for the body to calm down fully. 

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Zach VanderGraaff is a huge fan of helping people find the right information online, so when he heard Wesley was starting an online resource for betta fish, he knew had to get on board. Zach enjoys spending time with his three crazy boys and two dogs and caring for his pet fish.

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