why is my betta fish not moving

Why Is My Betta Fish Not Moving? 11 Common Reasons

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Wild betta fish are typically pretty active characters, spending much of their day patrolling their territory on the lookout for intruders, hunting for food, and seeking mates.

The behavior of captive bettas is similar, so if your pet suddenly stops moving, you’re right to be concerned about him.

In this article, you’ll learn the reasons why your betta might stop moving and what you can do to perk up your pet!

Why Is My Betta Fish Not Moving?

If you’re new to keeping betta fish, you’ll quickly learn that these fishy friends are all individual characters with their own personalities and behavioral quirks.

Provided you give your pet the correct environment, a high-quality diet, and enough mental and physical stimulation, he should remain healthy and happy.

But what’s the deal if your fish suddenly stops moving completely, and should you worry?

Let’s find out!

Your Betta Is Sleeping!

First, you should know that, just like you, betta fish sleep!

Betta fish are diurnal, meaning that they are most active during the daytime. Your betta needs at least 8 to 10 hours of light every day, followed by a period of darkness when he sleeps.

Without this clear day/night cycle, your fish will become stressed because he won’t understand when he should feed and become active and when he should sleep.


Your betta will also take regular naps throughout the day.

This is another betta “thing,” rather like darting to the water’s surface to grab mouthfuls of air into the labyrinth organ, and is perfectly normal behavior. Your fish might nap on a flat leaf or sometimes even on the substrate.

I once owned a betta fish that liked to take a rest by lying on top of the filter box well away from the outflow pipe. Another preferred to lie on the substrate with my Corydoras catfish!

As I mentioned earlier, bettas all have their own unique personality and behavioral quirks, so you simply need to get to know your fish!

The bottom line: Sleeping at night and taking naps throughout the day are both normal behavior in betta fish and are not a cause for concern.

Sick Betta

Lots of diseases can cause a sick fish to become inactive or have problems swimming. So, if your betta buddy suddenly stops moving, you must investigate to find out if he’s showing signs of illness.

Some common physical problems that can affect bettas include:

Swim Bladder Disease

The betta’s swim bladder is a structure that controls buoyancy and enables the fish to swim on an even keel.

If the swim bladder is compromised by overeating or disease, the fish might swim upside down or sideways. They may even be trapped, immobile on the substrate, and unable to swim up to the surface.

Bacterial diseases are common health problems that can cause swim bladder issues, and these can usually be treated successfully with an over-the-counter treatment.

During treatment, I recommend that you quarantine your fish to prevent the disease from spreading to his tank mates.

Bacterial Infections

Bacterial and fungal infections of the gills can affect the betta’s ability to breathe.

In this case, the fish might stop moving and lie on the substrate, respiring erratically or barely breathing at all.


Betta fish are susceptible to stress, which is one of the most common reasons your pet might stop moving.

The effects of stress have a massive impact on the fish’s health. Stress compromises the fish’s immune system, leaving your pet vulnerable to attack by diseases, parasites, and bacteria.

There are plenty of things that can stress betta fish, including:

  • Sickness and disease
  • Relocation to a new tank
  • Unstable water conditions
  • Too much or too little light
  • Introduction of new tank mates
  • Incorrect diet

So, it could be that bringing your betta home from the fish store and putting him into his new home aquarium has stressed him out.

In this case, your fish should settle down after a week or so once he’s familiarized himself with his tank and marked out a territory to defend.

Signs of Stress in Betta Fish

So, what signs of stress in your betta should you watch out for?

  • The betta rests on the bottom of the tank for long periods and is not moving.
  • The betta is swimming sideways, on his side, or unable to swim to the surface or back down.
  • Your fish is breathing heavily or displays irregular mouth and gill movement, possibly indicating a lack of oxygen in the environment.
  • Your betta fish is generally lethargic.

Bettas are naturally curious fish, so if your pet is hiding away among plants or in caves, that’s a sign he’s stressed or sick.

Incorrect or Poor Quality Diet

All fish, including bettas, need a high-quality, correct diet that meets their nutritional needs. If the diet is nutritionally deficient, the fish won’t thrive or have sufficient energy to remain active.

Bettas are primarily carnivorous, although they do eat some algae and plant matter, making them strictly omnivores.

In the wild environment, bettas are opportunists and hunters, using their upturned, teeth-filled mouths to snatch water-bound insects from the surface. The fish also feed on insect larvae, tiny crustaceans, worms, algae, and plant matter.

So, you can keep your betta fish healthy by replicating that wild diet in captivity by feeding your pet a balanced commercial betta diet of mini pellets supplemented by frozen meaty foods, such as bloodworms, daphnia, mosquito larvae, and the like.

Live Food in Captivity

I don’t give my fish live food, as there’s a risk of accidentally importing bacteria and parasites into my main tank and making all my fish sick.

However, I’ve always found that frozen food is just as nutritious, and my fish love it every bit as much as the “real” thing!


Bettas can be greedy fish, and this causes digestive problems, such as constipation. If your fish is obese, bloated, or constipated, he might lie on the tank bottom without moving simply because he’s physically unable to swim!

You can avoid overfeeding your betta fish by offering him only what he’ll eat in a couple of minutes twice a day.

I also like to nominate one day per week when I don’t feed my fish at all. That fasting day enables the betta to digest any food that’s still in his digestive tract before introducing more, preventing digestive issues and inactivity.


Captive betta fish have a 2 to 5 years average lifespan, although some fish might live longer than that. As your fish approaches the end of his life expectancy, you’ll often notice that he starts to slow down.

So, a betta of 4 or 5 years old might simply need more rest as he approaches the end of his life, so he spends longer and longer lying on the substrate or a comfy leaf.

Bored Betta

why is my betta fish not moving

Bettas are curious, intelligent fish that need plenty of stimulation to keep them happy. If your fish is bored, he might lie around without moving, purely because he lacks stimulation.

You can prevent this from happening by providing your betta with plenty of interesting decorations, such as caves, betta hammocks, rocky overhangs, and plenty of dense planting, including floating plants.

Bettas also enjoy interactive games with their owners. Why not spend time each day teaching your betta buddy to perform simple tricks, such as jumping through a hoop to get a treat?

Lazy Betta Fish!

Although some bettas are more active than others, many are, quite frankly, bone idle! These lazy bettas spend lots of their day sleeping or just lying around, not moving.

Bad Water Quality

Wild betta fish inhabit stagnant or slow-moving, heavily-vegetated waters where there’s little or no current. That led to the assumption that these fish can live in poor water quality and remain healthy.

That’s not true!

Betta fish are highly sensitive to water quality, and keeping the aquarium water clean, hygienic, and within the species’ preferred parameters is crucial for your pet’s health.

If the water in your betta’s tank is dirty, too cold, or the pH is incorrect, your pet could sit on the substrate and not move.

Remember that bettas are tropical fish that prefer a water temperature range of 76° to 82° F with a pH of between 6.8 and 7.5. Ammonia and nitrites should be zero, and nitrate levels must be 20 ppm or less.

Ammonia Poisoning

Your betta tank must have an effective filter operating to remove and process organic matter such as fish waste, uneaten food, decaying plants, and general detritus.

As concentrations of waste decompose, they produce ammonia, which is highly toxic to fish and invertebrates. Your betta will quickly succumb to ammonia poisoning if the levels are allowed to spike, and that could lead to him not moving on the bottom of the tank.

Ammonia levels in a properly cycled fish tank should always be zero. That’s achieved by running a powerful filter system, maintaining it correctly, and carrying weekly partial water changes of around 20 to 25 percent.

Tank Size

There are some environmental considerations to bear in mind, any of which could cause your betta fish to become lethargic or stop moving altogether.

Bettas need a reasonably generous area to claim as their territory, and they appreciate plenty of swimming space. These are naturally antisocial fish that don’t do well if kept in a busy, overcrowded tank.

Your fish needs a well-decorated tank of at least 5 gallons to thrive. If you keep your betta in a tank that’s too small, he will get stressed and could finish up hiding away and not moving.

Water Temperature Too Low

Betta fish need a constant water temperature that’s similar to that of the room where the tank is kept. If there’s a big difference between the two temperatures, the betta’s labyrinth organ could be damaged.

If your water temperature is too low, your betta’s metabolism will slow down, and he will become more and more lethargic until he appears to be constantly sleeping.

Check the temperature in your betta tank; if it’s too low, simply turn up the thermostat on your heater. Problem solved!

Egg-Bound Female

If a female betta fish becomes very inactive and stops moving, she might be egg-bound. That means the female is ready to deposit her eggs and might stop moving around as much as usual until the breeding cycle is complete.

Final Thoughts

I hope you enjoyed our guide to why your betta fish might not be moving around as much as usual. If you found the article helpful, please remember that sharing is caring, and hit the “share” button above!

There are many reasons why your betta might stop moving. He could simply be sleeping or resting. Senior bettas entering their final life stage tend to rest more than younger fish, and so do lazier specimens.

However, if you have a young betta, you should check your water parameters, look for signs of disease, and ensure that your pet’s diet is correct and that his tank is big enough.

Did your betta pet stop swimming around his tank? How did you solve the problem? Tell us in the comments box below!

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