Why Is my Betta Fish Not Moving? (Top Causes and Treatment Guide)

Dr. Mollie Newton
Published by Dr. Mollie Newton PHD| Senior Editor
Last updated: April 7, 2024
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All of us find great joy in watching our water-dwelling pets swimming happily in their homes through the glass of the aquarium. However, when we notice a sudden change in this behavior, it’s not uncommon for us to instantly believe that our fish could be dealing with a major issue in need of swift and significant actions.

I know my mind was racing when it happened to me. I searched all over the place for the answer and found it hard to find a concise guide.  After that, I sought to write my own contribution to the fishkeeping hobby.

Hold on for just a second, take a deep breath, and read on to find out what exactly may be going on before calling your local fish paramedic for support. Follow along to learn the answer to the question “Why is my betta fish not moving?”

Article Summary

  • Bettas may appear motionless due to sleep, requiring 8-10 hours of rest daily; it’s normal for bettas to rest after stress, like moving between tanks, illness, or changes in water conditions.
  • Reasons for bettas not moving include stress, improper lighting, poor water conditions, diet issues, age, and poor tankmates.
  • To keep bettas healthy, it’s vital to maintain water quality and promptly address any behavioral issues.

Why Is My Betta Fish Not Moving?

Blue and Orange Betta Fish Near Aquarium Substrate
Blue and Orange Betta Fish Near Aquarium Substrate

The first and most obvious answer to this question is that your betta fish is simply sleeping! Betta fish require between 8 and 10 hours of sleep per day, and will appear to be immobile during this phase, just the same as many other animals.

Using an automated timer can be a particularly handy way to keep your fish on a regular cycle, eliminating the stress of doing it for you and the stress of missing precious sleep for your betta fish!

An important part of ensuring the long-term health of your betta is to actually make sure that they’re getting a healthy sleep cycle by turning the lights down on a regular basis in order to establish a regular sleep pattern.

Is It Normal for Betta Fish Not To Move?

During sleeping phases and after times of stress such as being moved from one tank to another, following quarantine after sickness, and after feeding it is perfectly normal to see your betta fish laying still.

The fish is not sick or particularly in danger of death, but rather resting and de-stressing, much as we do following a particularly trying event.

Try to keep the time in transition as quick and painless as possible for your fish in order to avoid undue stress. If you’re having a hard time catching them, give it 30 minutes before trying again rather than stressing them out further.

However, if this continues for longer than a few hours or over the course of several days, it’s time to start considering other possible reasons for your fish sitting in your aquarium motionless.

Why Is My Betta Fish Not Moving Much?

If your betta fish is still swimming, albeit slowly or in odd places, these may be other signs that something is physically wrong and in need of attention.

The fact that it’s still moving is a good indication that the betta fish isn’t dead, but may need some help.

Reasons Why Your Betta Fish Is Not Moving

Betta Fish at the Bottom of the Tank
Betta Fish at the Bottom of the Tank

There are several possibilities when looking at a sudden change in the behavior of our bettas. These include:


Stress is one of the most common reasons to consider when looking at why your fish may stop moving, and has a huge effect on their health overall.

While it can be hard to know just what to look for when it comes to stress in our silent friends, if any of these events have happened it may be something to consider.

  • Recently being moved from one tank to another
  • Overcoming illness
  • Sudden changes in water conditions, including water temperature and pH which can lead to temperature shock
  • Not sleeping properly due to improper lighting or poor water conditions in the tank
  • The introduction of another betta tank mate to the aquarium of a male betta. New tank mates will likely lead to a period of increased aggression and stress as your betta adjusts to the new living situation and will return to normal after a few days
  • A recent feed of something too difficult to digest, such as an un-shelled pea

Signs That Your Betta May Be Stressed 

  1. Betta fish sitting on the bottom of the tank
  2. Swimming towards the surface, or swimming sideways (also a common sign of swim bladder disease)
  3. Breathing heavily, or with irregular gill and mouth movement (which may also indicate a lack of oxygen in the tank) A bubbler might be able to help with this.
  4. A generally lethargic appearance, swimming slowly towards food or staying still at the bottom.

Resting or Sleeping

As stated earlier, your betta will require around 8-10 hours of sleep at a time, which will be determined by the amount of light you provide for your fish throughout the day.

We recommend dimming the lights regularly, which doesn’t necessarily have to be during the normal day night cycle outside if for some reason this doesn’t work with your schedule. Sleeping on the bottom of the tank is not uncommon!


Food for Aquarium fish
Food for Aquarium fish

Feeding your fish a proper diet with enough protein is key to helping them grow and live healthily. Good sources of protein include insect larvae (such as mosquito larvae,) brine shrimp, and flakes designed for bettas from your local pet store.

Feeding your betta something it wouldn’t normally be able to digest, such as plant matter or certain processed human foods can also lead to extra stress and cause your fish to appear stationary on the bottom as it struggles to digest!

With diet, a good indicator that something is off is the presence of uneaten food on the bottom of the tank.


Take note of when you feed your fish, and if you notice that after 30 minutes there is still food remaining, remove it.

This not only keeps your tank clean of harmful ammonia buildup as the food decomposes, but can be an indicator of whether your betta fish is eating enough food.

If you notice a lot of leftover food in the betta tank, it could indicate that your betta might not be eating properly, which can be a sign of illness.


As our betta fish age, they will naturally slow down as their normal bodily functions begin to wear down with time. With the average lifespan of a betta fish in captivity ranging between 2 and 5 years, a lethargic looking betta fish who is 4 years old may simply be slowing down as they mature.

Lazy Betta

While it may seem somewhat fanciful, a “lazy betta fish” if likely one that is a sick fish. These normally hardy fish should be swimming around regularly after food, rather than letting it fall in front of them.

Unlike humans, betta fish are very unlikely to exhibit behaviors such as “laziness,” and seeing your fish not moving should be a cause for concern.

Poor Water Quality

Maintaining high quality water in your aquarium is one of the keys to keeping your betta fish healthy. When we refer to poor water quality a common visible indicator is being able to see sediment floating in the water column of your aquarium.

Betta fish are just as susceptible to bacterial infections, fungal infections, and other illnesses and bad water quality can make these happen more regularly.

Use a test kit regularly and measure the temperature often to determine how things are doing in your tank and prevent future problems for your betta


High ammonia levels are typically caused by uneaten food, the presence of dead or decaying matter, and high concentrations of waste.

High ammonia and nitrate levels is one of the most immediate concerns for your betta and can lead to ammonia poisoning and death for your betta if not corrected.

Here’s a quick and informative video about ammonia spike in fish tanks

Ammonia Poisoning In Fish

Prevent poor water quality in the betta tank with a regular weekly water change or the use of a water conditioner. Cycling the water in your betta tank on a regular basis is the best way to keep water conditions up to par and prevent a dead betta.


Having too many other fish as tank mates in the same tank as your betta can lead to serious problems if your filtration and aeration systems aren’t in working order. More fish mean more waste!

Keep in mind that it’s also not advisable to keep two bettas together due to their aggressive nature.

Environmental Factors

The main environmental concerns for betta are:

  • Aquarium Size Your betta needs the proper amount of swimming space in order to stay happy and healthy, and we recommend a minimum of a 3 gallon aquarium size for a single betta. If planning on more than that, consider an additional 1 gallon tank per 1 inch of fish added to the tank. Less than this will lead to a betta who can’t move around enough, leading to lethargy.
  • Proper Filtration – An improper amount of variety of filtration in your tank can lead to all sorts of problems down the road. Make sure that both the natural biological filtration from bacteria and the artificial ones from pumps and gravel filters are working properly through regular check-ups and cleaning.
  • Heaters – Water temperature is very important to a tropical fish like the betta. They prefer a temperature range of 75-80 degrees, which may necessitate a heater for the tank. Any lower than this and your betta will begin to swim slowly and become more lethargic as its body struggles, and may appear to be sleeping.
  • If things are too cold, simply raise the temperature to see your betta swim like normal. Temperature shock is the term for when a rapid change in aquarium temperature forces your betta into a state of stress, and can take the appearance of a common illness, often causing fish to no longer swim and stop moving.


Betta Fish at the Corner of a Tank
Betta Fish at the Corner of a Tank

There are a few diseases that can lead to your betta appearing to sleep or have difficulty swimming including swim bladder issues and infections.

  • Swim bladder problems – Certain bacterial diseases can cause a swim bladder issue for a betta, causing it to swim sideways or even upside down. The best treatment for a swim bladder issue is to consult your local fish store for the proper medication, and to quarantine the affected betta fish in a separate tank so that the disease does not spread.
  • Infections – Diseases of the gills and mouth can cause your betta’s gills to work improperly. A noticeable sign of this is irregular gill and mouth movement, or inflamed/redness to the gills.
  • Fin Rot – Another common sign of bacterial disease in fish.
  • Bloat – When your fish has eaten bread or too much feed or has an infection in their body or a swim bladder disease, they may have enlarged organs and have difficulty swimming. The affected betta will sit on the bottom of the tank as it cannot properly maintain its buoyancy.


A female betta who is ready to lay (commonly referred to as being egg bound,) will likely slow down as she begins the process of laying.

If you notice that after she has completed the breeding cycle that things have not returned to normal, consider looking at the water parameters in the tank and her physical health.


In today’s article we’ve looked at the many reasons why a betta fish may not be moving around as normal in your tank.

The most common reasons for seeing an unmoving betta fish include simply sleeping, an illness such as swim bladder disease, or being overstressed from the addition of too many new betta tank mates.

Keeping a close eye on our betta fish is the best way to be aware of changes in behavior and know what is an actual cause for concern versus being completely normal betta behavior.

Additionally, you can give betta toys to keep them entertained and provide them with mental stimulation. Having toys in their tank lowers stress level and help reduce aggression, making them healthier.

Feel Free To Share!

As always we hope that today’s article on betta fish has been helpful in answering your questions.

Feel free to share this article with other fish fanatics in your life, and we wish you the best of luck on your aquarium journeys!

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