What are the signs of a stressed betta fish?

In this blog we will discuss signs of a stressed betta fish, the reason behind their stress and how to fix their stress.This blog will help betta enthusiasts to understand their behavior leading to stress.


In this blog

  • What are the signs of a stressed betta fish?
  • How do bettas behave when they are under stress?
  • How to help a stressed betta fish?
  • Summary 
  • Frequently asked questions
  • Reference 

What are the signs of a stressed betta fish?

Like all vertebrates, fish have a general physiological response to a threatening situation called stress.The stress response begins almost immediately after sensing the stressor.

  • Strange swimming patterns
  • Crashing at the bottom of the tank
  • Rub themselves on gravels or rocks
  • Fin locking

How do bettas behave when they are under stress?

Faded/muted color in bettas

Bettas lose their color due to stress, old age, injury and disease. Bettas also naturally change color, especially if they carry the marble gene.

If your betta is black, you shouldn’t be too concerned unless they show signs of other diseases.

So, if your bettas are losing color, it may be the sign which indicates they are under stress and it could be due to bad water quality or ammonia spikes.

They lose their color when they get bullied by other tank mates or they may be experiencing it due to overcrowded tanks.

Clamped fins of bettas

Clamped fins is the condition in which the betta fish keeps its fins folded and held against the body.The fins are not fan-shaped and the fish is lethargic.

It does not indicate a particular illness and may be the first sign that the fish is unhealthy due to behavioral changes and is experiencing extreme stress.

Stress stripes in bettas

Betta stress lines or stripes are bettas’ reaction to sudden changes or unfavorable conditions in the aquarium. 

Your fish may begin to lose its shiny color and may have light and/or dark vertical stripes on the sides of its body.

Poor appetite in bettas

Feed your betta only high quality food and make sure they get a balanced diet and sometimes small water changes can cause them to stop eating.

Check the water parameters and see if there are any problems.If the water temperature is too low, it can slow down his metabolism, causing them to eat less.

Lethargy in bettas

If your fighting fish looks lethargic and spends time lying on the bottom of the tank, they may be sick or stressed.

In fact, due to a weaker immune system, these fish are more likely to suffer from diseases.Diseases such as ich,bloating, dropsy and others can lead to a weakening of the fighting fish.

Hiding behavior in bettas

Bettas will be under a lot of stress and may refuse to leave his hiding spot until the non-compatible tank companion moves to another part of the aquarium.

Bullying is a common reason why fighting or betta fish hide in a community aquarium.

Darting behavior in bettas

It’s normal for bettas to sometimes dart around the tank. As well as sly swimming behavior, you may notice them rubbing against rocks and hitting darts at the bottom of the tank and rubbing gravel.

Bettas might get stressed or maybe he could see his own reflection, in which case he’s swimming aggressively to fend off the other betta.

If a chemical is introduced into the water that the betta fish does not like, it can swim in circles.

How to help a stressed betta fish?

Water changes in bettas tank

  • Change the water frequently to keep nitrate and ammonia levels low.To ensure the long-term health of your fighting fish, you need to change the water in your aquarium frequently.
  • This is due to the fact that the waste excreted by this fish contains large amounts of ammonia and nitrates.
  • A 10-20% water change every 7-10 days is most beneficial for the health of betta fish assuming you are running a filter.
  • You can also change the water 20-30% every 2-3 weeks, but smaller changes are better for a stable water environment.

Water parameters monitoring in bettas tank

  • Water should be monitored everyday to check the levels of organic pollutants in bettas tanks to maintain pristine water conditions.This will keep bettas healthy and stress free.
  • Ammonia is a by-product of fish excrement and other rotting debris such as inedible fish feed and dead plants.
  • Even low levels of ammonia can lead to gill damage, weakened immune system, and fin rot.
  • Ammonia testing is a must, as most fish keepers do not house bettas in filtered circulating aquariums.

Adding water conditioners in bettas tank

  • Try adding water conditioners such as API stress coat aquarium water conditioner, which reduces fish stress by up to 40% by removing dangerous toxins.
  • Fluval water purifiers make water safe for tropical fish by neutralizing chlorine, chloramines and harmful metals in aquarium water.
  • Formulated with pure herbal extracts, it also significantly reduces the stress on fish caused by transport, handling and acclimatization.

Healthy and balanced diet for bettas

Betta fish cannot eat plant foods and, contrary to what some fish shops will tell you, they do not eat plant roots.

The best diet for fighting fish should include a variety of freeze-dried foods, live foods (mosquito larvae, brine shrimp, bloodworms), and high crude protein fish flakes and/or pellets.

Best commercial food for bettas:

  • Premium freeze dried food:San Francisco bay freeze dried bloodworms.
  • The best flake food: Omega one betta flakes.
  • The best pellet food: Ocean nutrition atison’s betta food.
  • The best pellet food: Ocean nutrition atison’s betta food.

Avoiding overfeeding bettas

Overfeeding is the most common mistake new betta fish owners make.

If you feed your betta fish too much, the debris can clog the filter and decompose into toxins that are harmful to the betta fish.

Leftovers or uneaten food causes elevated levels of nitrates and phosphates, which contribute to increased algae growth.

Poor water quality also hinders the growth of fish, making them lighter in color and less resistant to disease.

Compatible tank mates for bettas

Female bettas are usually less aggressive and less territorial than male bettas and this gives you more freedom in choosing their tankmates.

For female bettas,you don’t have to worry about the color of their aquarium buddies,this means you can keep flashy colored fish in the aquarium alongside female bettas.

  • Guppies.
  • Kuhli loaches.
  • Neon and ember tetras.
  • Ghost shrimp.
  • African dwarf frogs.
  • Cory catfish.

Male bettas easily get stressed around tank mates,they cannot be kept with tank companions.

They are better kept alone in a solitary tank.It is their aggressive behavior,which doesn’t let other tank mates including their own type to stay together in similar tanks.

Bigger and spacious tanks for bettas

  • The ideal aquarium size for bettas is 3-5 gallons or more for one male or female betta.
  • For bettas, the tank should have at least 3 gallons. If you plan to keep a lot of community fish, according to this formula, the aquarium should provide 1 gallon of water for every inch of fish that grows.
  • The natural environment of the betta is shallow streams,so they prefer an aquarium longer than it is high.
  • A deep tank is not beneficial for the betta, while a horizontal tank allows the betta more swimming space and easier access to the surface.

Correct water parameters for bettas

Correct water parameters for betta fish:

  • Water temperature: 75°-81°F or 23.8°-27.2°C
  • Ammonia and Nitrite levels: 0 ppm.
  • Nitrate levels: <20 ppm.
  • GH: 3-4 dGH or 50-66.7 ppm
  • KH: 3-5 dKH or 53.6- 89.4 ppm
  • Water pH: 6.5-7.5.

Providing lots of hiding spots to bettas

Bettas like to swim alone and also need comfortable hiding spots. Aquatic caves or densely planted nooks are great for keeping bettas safe and secure when they are stressed.

In their natural habitat,bettas can easily prey on large fish,so they prefer areas with lots of caves.

If your Betta feels like it’s on the move too much and there’s nowhere to hide,you’ll always stick to the same hiding places.


  • When betta fish are stressed, weird swimming patterns often occur.
  • If the fish are swimming desperately without going anywhere, crashing at the bottom of the aquarium, rubbing against gravel or rocks, or fixing the fins sideways, it can be very stressful.
  • Water changes should be done either everyday or weekly depending upon the size of the aquarium and filters.This will keep the levels of ammonia and other organic pollutants in check.This will keep their stress levels low.
  • Aquarium water should be monitored everyday with the water testing kit to maintain pristine water conditions,for your bettas to live stress free.
  • A good quality water conditioner is always important to keep their aquarium water free of toxins,which could make bettas stressed.
  • Providing a healthy and balanced diet to bettas so that they don’t get stressed if they are underfed or poorly fed.This might lose their finnage colors.
  • Keeping bettas with compatible tank mates will keep the tank environment stress free,so choose their tank mates wisely to avoid fights and aggression.
  • Always keep your bettas in bigger and spacious tanks,because smaller and compact tanks will inhibit their growth and it will even be suffocating for them to stay in such smaller and overcrowded tanks.
  • Overcrowded tanks trigger aggression which ultimately cause stress in bettas.Bigger is always bettas in case of bettas.
  • If bettas are undergoing lots of stress they should be given lots of hiding space in their aquarium,like their original habitat.
  • Stress is not at all good for betta fish and it might reduce their lifespan too,so avoid giving stress to them.
  • Provide all the necessary things in their aquarium to keep them happy and stress free.

Frequently asked questions

Where do bettas hide,when they are under stress?

Bettas like to swim alone and need a comfortable hiding spot.Aquatic caves or densely planted nooks are great for keeping bettas safe.

Do colorful or flashy tank mates stress bettas?

Yes, flashy and colorful tankmates trigger bettas aggressive behavior and such aggressive behavior can stress them easily.It would be better to avoid flashy tank mates in bettas tank.

Do fin-nippers stress bettas?

Yes,if bettas are kept with fin-nippers then definitely,it will stress them.The fin-nippers will attack their long flowing fins and is one of the reasons to avoid such tank companions in bettas tanks.

Does stress affect bettas swimming patterns?

Yes, when stressed, fish often develop strange swimming patterns.If bettas are swimming strangely without moving anywhere, they may be under a lot of stress.