Betta Fish Lying at the Bottom of the Tank – 10 Possible Reasons

Betta fish are the most common freshwater fish for aquariums. They are cherished due to the different shapes and colors in which they can be found.

They are also known as Siamese fighting fish and have striking personalities and behavior traits.

Due to their inherent nature, they often lay on the bottom of the tank.

Usually, it is not a matter of worry.

However, if your fish is lying on the bottom of the tank for a long time and doesn’t look too well (breathing heavily, discoloration, not eating) then it could be a matter of concern.

There are many reasons why your betta fish is lying at the bottom of the fish tank.

In this article, we will dive into all the possible reasons that may have caused your betta fish to be staying at the bottom of the aquarium.

Reasons Why Betta Fish Lays at the Bottom of the Tank

Betta fishes are one of the most popular pet fishes in the world. Being delicate, they require some amount of care.

If you find that you’re Betta fish is spending a lot of time at the bottom of the tank, it certainly something you should look into (as Betta’s are known to swim mostly at the top of the aquarium).

Many times, there may be nothing to worry about, but in some cases, it may be something you need to investigate more.

Below we have covered the most common reasons

Asleep or Resting

It is a common habit of Betta fish to find a good place on the bottom of the aquarium where it can lay easily and take a nap.

This trait has made the fish very popular among aquarium keepers.

Betta fish sleep in portions, multiple times at night. They follow the same sleep rhythm cycle humans do.

This means they behave like us – active during the day and sleeping during the night.

If your Betta fish does not get enough sleep, it is possible for you to find them napping at the bottom of the tank.

In the wild, the betta sleeps on a big leaf. One thing to note is that Betta sleeps in the dark.

To check whether they are sleeping or resting, turn on the lights. Lights will make them active.

It’s Being Lazy

Better is one fish that likes being lazy. In pure laziness, it will go and lay at the bottom of the tank.

If the fish is moving its front pelvic fins while lying down, it is simply chilling out.

Betta does not like swimming around a lot. It takes breaks and lays down at different places inside the aquarium.

If it’s eating normally and otherwise exhibiting normal behavior, there is nothing to worry about.

Betta Is Stressed Out

If you keep the lights on throughout, this will confuse the fish.

As Betta sleeps at night when there is darkness, the presence of light will make him move continuously.

After a while, the fish will be exhausted and stressed out.

Switch off the lights at night and let your Betta sleep. Ideally don’t keep the fish tank lights on for more than six hours.

If you are keeping Betta in a small aquarium, the fish will feel confined and stress out. Keep the fish in the tank which holds more than three gallons of water.

This is the minimum for Betta. A ten-gallon aquarium is ideal for the fish.

This is because they like to have a lot of personal space where they can explore and retreat.

A stress-free environment is a must for Betta fish. An efficient way to reduce stress levels is by adding live plants.

You can also add water plants that remain afloat on top of the aquarium. The addition of plants creates a natural environment for the fish.

This helps fight stress along with improving the aesthetics of the tank.

The betta fish do not like being with other fish. However, they can be kept along with certain snails and shrimps (mystery snail and ghost shrimp).

They will help keep Betta healthy and free from stress.

Fast Speed of Filter Currents

If the aquarium filter gives out strong and fast currents, the Betta fish does not move much and stays at the bottom of the aquarium.

Most filters come with a valve that controls the filter flow. Lower the filter power with the help of a valve and that will make Betta fish active again.

If your filter does not have a valve, purchase a filter which has an adjustable flow feature.

Controlling the flow is very important for Betta fish as it is a slow swimming fish. Some other alternatives include dispersing the water flow with plants or decorations.

You can also drill holes in the filter that will reduce the pressure and slow down the flow of current.

The Temperature of the Tank Water Is Too Low

Betta fish are tropical and live in waters having a temperature of 75-82 degrees Fahrenheit (24-28 in celsius).

When the temperature of the water goes down, the metabolism of the fish also slows down.

Slow metabolism causes Betta to become lethargic and spend a lot of time at the bottom of the aquarium.

Lower temperatures also absorb oxygen slowly. This can also be problematic for the Betta fish.

Raise the temperature of the water tank slowly.

Use a good water heater to warm up the tank to the required temperature. Sudden changes can stress the fish out, and also kills the beneficial bacteria.

The Temperature of the Tank Water Is Too High

Betta fish can get extremely stressed with water temperature surges. This particular species generally enjoys warm temperatures.

However, during the summer, it is possible for the water to get excessively hot.

If that is the case, then your extra hot water tank is releasing way too much oxygen, leaving them with extremely little of it to breathe.

This can negatively affect your Betta fish because without oxygen.

They will be gasping for air while staying at the bottom of the tank.

If your water tank is not able to provide your Betta fish with a good amount of oxygen, it can become a serious issue.

If you do not keep a constant check on the water tank temperature, your Betta fish could easily catch a disease that may or may not be fatal.

Use a fan to blow directly on the water surface of the tank.

You can also air-condition the room where the aquarium is kept. Also, make sure you remove the aquarium from the area of direct sunlight.

Tank Size

Betta fish need a minimum of five gallons of water to live stress-free.

If your Betta fish is cooped up in a small tank, there is a high chance it is unhappy.

Tiny and congested fish tanks do not give your Betta fish enough room to swim around and explore.

Lack of interest leads your Betta fish with nothing to do, so it chooses to lay at the bottom of the tank our sheer boredom.

Always give your Betta fish ample room to explore and exercise.

Tank decoration items and plants are a great way to spark your Betta’s interest and help it stay active.

However, be careful not to overcrowd the water tank under any circumstances.


Betta fish do not live a very long life because this species has a short life span.

Even if you provide your Betta with the best conditions, they can only live up to a maximum of five years.

If your Betta fish has been with you for a pretty long time, it is possible it may be entering its old age.

Just like any other living being, Bettas also suffer through old age effects and slow down.

Naturally, they become less active as they get older. This means that they do not have enough energy to swim around in their fish tank like they used to.

If your fish tank has younger fish, you will notice how your old Betta might have a problem keeping up with them.

In comparison, they will definitely feel weaker, slower, and even lethargic while staying at the bottom of the tank.

If old age is the cause, your Betta fish probably prefers to rest more than it did before.

While staying at the bottom of the tank, the Betta fish could be laying down, sleeping more often, or taking considerably more time to rest.

They prefer lying around on the bottom of the aquarium. As the Betta age, they lose the energy to swim and explore for a long time.

The maximum age that Betta fish achieve is 4 to 5 years. After five years they become lazy and susceptible to diseases.

Betta Has Swim Bladder Disorder

If the betta fish is lying at the bottom of the tank, and not moving for a long time, it could be that the fish has swim bladder disorder.

The stomach swells causing hindrance to the proper functioning of the bladder. As a result, the fish spend most of their time lying down in the aquarium.

They are unable to move due to the difficulty they face with their swollen body. They may also start floating to the top, sideways for upside down.

This is often caused due to overfeeding or constipation and can be treated by feeding foods that contain more fiber.

A good approach is to fast the fish for one day and then give high fiber food. A high-fiber diet should be given every two days until the swelling subsides.

Later the diet can be continued to once per week. Some good examples of high fiber food include boiled pea, bloodworms, and daphnia.

Soak the food pellet for 2-3 minutes in aquarium water. This will take care of the overfeeding as the food will swell up outside the fish body.

The betta fish will feel full after consuming little.

Too Much Ammonia in the Water

When the Betta fish is exposed to excess ammonia, it will lay on the bottom of the tank and start breathing heavily.

Such situations require a quick fix-up. Check the water parameters with the help of a good kit.

Find out the pH and nitrates level in the water. You can find the water tank test kit online or offline at any pet shop.

A high level of ammonia could be due to an overstocked tank where the fishes produce too much waste.

Overfeeding the Betta fish will also lead to food becoming wasted and turning into ammonia. Do not overfeed the fish. Monitor how much Betta consumes in one go.

What you have to do is to change the water of your aquarium up to 50%. Do at least 20% water change every week.

If the fish is female and not constipated, a swollen stomach could also mean that the fish is eggbound. You cannot do much in such cases.

The Fish Has an Underlying Disease

Fish have low immunity compared to other fishes. Sickness is another reason why the fish lays at the bottom of the tank.

Along with lying down, it will exhibit a weird behavior (not eating, gasping, not moving), loss of coloration, white dots on scales, cloudy eyes, etc.

Put your Betta into a quarantine tank. Make sure the water parameters are perfect for the fish.

Take the help of an expert in dealing with betta fish diseases. Keep the water clean, oxygenated, and feed your fish properly.

To treat an infection, add Epsom salt (one tablespoon per five gallons).

If your Betta’s fin appears to be rotting away, consult a vet for the appropriate next steps and also make sure the tank is thoroughly clean.

If the fish has lots of white spots on its body, it has contracted ich. After taking the fish to the quarantine tank, raise the temperature to about 80 degrees Fahrenheit.

Maintain the temperature for 48 hours and add formalin.


If you see a betta lying normally and peacefully at the bottom of the tank, there is no cause for worry.

If it is healthy and eating right, then it is just following its inherent nature.

Tick the above checklist to find out why your betta is lying at the bottom of the tank. You have to observe the fish and follow its patterns.

After monitoring closely, you can yourself reach the conclusion of whether it is just the habit of the betta fish or an issue that needs correction.

All the best!

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