Why Your Betta Fish is Laying at the Bottom of the Tank?

fish at bottom of tank

If your betta fish – also known as the Siamese fighting fish – is sleeping, resting, or has reached old age, it is normal for it to lay at the bottom of the fish tank.

However, in some instances, it is not normal behavior for betta fish, and it might be a case of illness, poisoning, a small tank, or poor water conditions.

betta fish laying on bottom of tank

Reasons Why Betta Fish Is Not Moving

There are multiple reasons why your betta fish is not moving or laying still at the bottom of the tank. It might be that the fish is resting and taking a nap. But resting at the bottom of the tank can also be a negative thing. 

Some of the other possible explanations include illness, old age, poisoning, stress, and depression. All of these reasons slow betta down and can cause them to lay down more frequently.

If you find a betta laying, the best tip is not to panic and to take the time to observe how the fish is behaving.

betta laying on bottom of tank

Sleeping Betta Fish

If your betta has long fins, as most do, it might not be able to swim as effectively. It might be tiresome for a long-finned betta to swim all the time, and sometimes it is comfortable to rest at the bottom.

Breeders created betta to be an ornamental fish, which results in long in a massive variety of colors. However, some of these fins are long enough to disable the fish.

This is especially true if you have a half moon, over half moon, rose tail, or similar tail type. These tails are massive and can greatly weigh down your betta.

They simply are not able to swim as normally or constantly as they should so they end up sitting, or laying at the bottom of the tank.

betta fish laying on side

If they are in one spot for a very long time and they are not moving, but their gills are moving regularly and they are breathing at a steady rate, this probably means that your betta is sleeping.  

Betta, like most fish, does not have eyelids. This means that they sleep with their eyes wide open because that is the only thing they can do. So, if the betta is not moving and it looks like it is staring into the fifth dimension, it is probably sleeping.

Older Bettas like Resting at the Bottom

betta fish staying at bottom of tank

As bettas grow older, they tend to slow down. While this can happen as young as a year and a half old, other bettas may not start to experience symptoms of old age until they are three or four years old.

As they age, the metabolism of older betta fish will slow, their color will grey, and they will be more lethargic. They may begin to sit at the bottom of the tank more often, which can cause many pet owners to panic.

Ammonia and Nitrate Poisoning

Poisoning is one of the two most common causes of lethargy and inactivity, so it is best to rule those out first.

Ammonia and nitrate poisoning are unfortunately very commonly seen in bettas. Many people have bettas as their first fish pet and most do not do enough research into caring for their new little friend.

When fish waste or fish food begins to dissolve into the water, it turns first into ammonia and then into nitrite. After around a month, these two compounds will turn into nitrate, which is only harmful in long term. On the other hand, ammonia and nitrite poisoning kill, and quickly.

betta fish sitting at bottom of tank

The first thing you want to do is check the activity of the betta fish. If it is breathing very heavily and laying at the bottom of the tank, he might be flaring really hard at himself. This might really tire the fish.

If you did not cycle your tank and your fish is lethargic and slow-moving, test your water parameters immediately. If the tests come back negative for ammonia and nitrite and show some nitrate, your tank is in good working order.

You should next check for illnesses.

Common illnesses

Once you have made sure that there is no case of ammonia or nitrate poisoning, it is time to check for illnesses, the second most common causes of the slowing down of your betta fish.

You have to monitor what your betta fish looks like. If it is looking very pale and laying at the bottom of the tank, then it might be sick. A really big red flag is if your betta is upside down.

There are many common betta illnesses. The illness can all manifest as the same symptom, so it can be difficult to diagnose your fish. Long fins are easy to determine and they only cause sitting issues in males.

lethargic betta fish

If your betta swims but appears to be dragged down by its fins, or its movement does not extend all the way to the tips of the fins, then the fins are the most likely cause.

Stress can be difficult to identify in fish, but it does happen. Try to identify if your fish has any nearby stressors such as vibrations, reflections in the tank, or other tank inhabitants, or see if the tank is in a high-traffic area.

If there are any of these stressors, remove them before attempting any other remedy.

Fin Rot

betta fish on bottom of tank

Fin rot is incredibly common in bettas, particularly if they have long fins.

The beginning stages of fin rot may be hard to identify, as the edge of the fin may just look slightly wobbly or undulating. As it progresses, the fin starts to appear ragged and normally has a black, grey, or even white edge to it.

More frequent water changes, antibacterial medications, and hydrogen peroxide swabs often solve this problem.

Velvet and Ich

sick betta fish laying bottom

Velvet and Ich are two common parasitic infections that are treated with the same general medications.

Velvet appears as a golden sheen on your betta while it looks like grains of salt. Both need to be treated quickly and for a relatively long period of time.

Bacterial Infections

Bacterial infections are also unfortunately common, though it can be difficult to identify a specific strain.

It can appear as fluffy spots on a betta, red inflamed veins, a general lack of activity, strange colors, whiteness on the body, and many other symptoms.

It is best to treat this with strong antibacterial medications that treat both gram-positive and gram-negative bacteria.

Swim Bladder Disease

fish laying on bottom of tank

If your betta is swimming awkwardly and then it might also be the case of swim bladder disease, which is fairly common in bettas. However, it is very uncommon for it to be fatal. In fact, in just a few days of treatment, you should be able to cure your betta.

Swim bladder disease is a term used to describe any ailment whether it is an illness, damage, or a situation that causes your betta’s swim bladder to work properly. There are a number of different common causes of swim bladder diseases including overfeeding and constipation.

In a vast majority of cases, swim bladder disease is caused by overfeeding. Bettas are a particularly gutty fish and they will never stop eating even when they are full. This often makes them constipated, which can have an effect on their swim bladder.

Not only can this cause them to become constipated, but it can also make fatty deposits build up in their bladder.

A less common cause of swim bladder disease is a shock. If something drastic has happened in your tank, this can result in stress or shock that can have an effect on your betta’s swim bladder. The shock can be caused by a whole range of factors including a sudden temperature change.

betta fish not swimming

Another reason for swim bladder disease can be parasites. Parasitic worms can infest your betta’s stomach and intestines, which can make it a lot harder for your betta to swim. Bacterial infection can also lead to swim bladder disease.

This, along with parasites, is likely due to poor water quality. If your betta is suffering from a bacterial infection, a swim bladder disease will be a likely symptom along with many others.

If a bacterial infection has gotten so bad that the swim bladder is being affected, then euthanasia may have to become an option. If you notice swim bladder disease along with severe bloating and pinecone scales, then you should start treating your betta for dropsy.

Troubled swimming and buoyancy problems are the most common symptoms of swim bladder disease. Floating on the surface, sinking to the bottom, and lopsided swimming are other common symptoms that will help you identify swim bladder disease.

Distended bellies or curved backs are another telltale sign of constipation or overfeeding.

A Small Aquarium

betta fish sitting on bottom of tank

It is one of the most commonly known myths and a great misconception that bettas can be kept in a fishbowl or a vase.

There are a few pet stores that keep the betta fish in small containers. These stores are able to sell their fish more easily as they tell their customers that there is no need to buy a large tank or any additional equipment for the new pet.

Betta fish are known to be able to survive in small tanks but the ideal space for a single betta is an aquarium of a minimum of three gallons.

A smaller tank space means that the betta fish is not able to move around a lot and this can lead to lethargy. This is one of the reasons why you might be seeing your fish laying at the bottom of the tank.

Temperature Fluctuation

betta fish laying on side at bottom of tank

When you find your betta fish breathing really heavily, it is also a good idea to check the water temperature.

Betta fish do not function well in cold water. This is because they are tropical creatures that thrive in temperatures between 24 to 28 degrees Celsius.

If the tank’s water temperature is below 24 degrees Celsius then this could lead to the problem of swim bladder disease. When the water temperature in your tank drops below the idle temperature, it is going to cause your betta’s digestive system to slow down.

With the slowing down of the digestive system, your betta’s more likely to become constipated. It can also lead to the swelling of other organs.

If you notice that the temperature of the tank is cold, ensure to raise it to around 24 to 28 degrees Celsius.

Wrong pH

betta fish bottom of tank

If you find your betta fish laying at the bottom of the tank you might also want to check the pH levels of the aquarium water.

Ideally, the water’s pH level should be neutral at 7.0. Any fluctuations in the pH level, above or below the neutral level, can lead to sickness in your betta fish.

In order to maintain the pH level of your fish’s tank, it is recommended that you buy a pH treatment from your local pet store. These treatments regulate the pH level of the water and are a cost-effective solution.

It is important to note here that any changes to the water conditions should be made at a gradual pace. If your water’s pH level is higher or lower than 7.0 then it is advised that it is adjusted over time.

Sudden changes should not be made as they stress bettas and can potentially cause them harm.

Lack of Filter or Use of Improper Filter

fish on bottom of tank

It is important to use proper filtration for the tank of a healthy betta. If the tank is not filtered, you will need to manually change the water of the tank on a frequent basis in order to maintain water quality and keep out toxic debris.

Ideally, you should have both natural and artificial systems working. The natural biological filtration system provided by bacteria works best when combined with artificial filtration from gravel filters and pumps.

Regular check-up and cleaning routine for the filters is also crucial.

When choosing a filter, you should keep the nature of the betta fish in mind. These fish do not prefer to swim in turbulent or moving water so you should choose a low-flow filter to reduce water movement. In case you end up selecting the wrong kind of filter, it will impact the way your fish is moving and its motivation to explore.

With the use of an improper filter, you will most often than not see your fish stationary at the bottom of the tank. This often happens when the filter is too strong and it is impossible for the betta fish to move around.

Improper Eating Habits

fish bottom of tank

If you are feeding your betta fish the wrong kind of food, it might lead to them becoming lethargic. This means that do not spend a lot of time exploring and end up moving lesser than expected. You might often see them at the bottom of the tank in a resting state.

What bettas need is good sources of protein such as insect larvae (such as mosquito larvae,) brine shrimp, different types of worms, daphnia, and flakes from any local pet store.

Instead, you are feeding them something that they are either not able to digest. Plant matter or processed human food causes stress to the betta fish and this is one of the primary reasons why they are found to be stationary at the tank’s bottom.

If this is the case, a good indicator of this can be uneaten food at the bottom of the tank. If thirty minutes after you have fed your fish, the food is still uneaten, it might be a good idea to remove it and try something else. This will also prevent the buildup of ammonia due to the decomposition of food.

Without proper diet and nutrition, bettas will not find the energy to swim a lot.

Lack Of Habitat Features

betta fish not eating and laying at bottom

Live plants in a betta tank make them happy for a couple of reasons. The first is that it gives them something to swim through which keeps things active and interesting. It gives them something to do instead of just swimming back and forth all the time, and they have something to play with.

Betta fish get tired of swimming all the time and without the additional activities provided by live plants and other additional features, you might find them laying at the bottom of the tank most of the time.  

When adding items to your betta’s tank, it is important to keep in mind their fluffy and sometimes long fins. They are almost like little pieces of art. Adding things that can possibly damage those fins is a big no-no.

If you are not careful with the type of decoration you put in the tank with the fish, they might quickly swim through sharp objects and shred those fins to pieces.

This can be another reason why your fish is immobile at the tank’s bottom.

Wrong Tank Mates

betta fish laying on side

By nature, betta fish struggles to be around other tank mates and it causes them a huge amount of stress and discomfort. Too many other fish in the same tank as the betta fish leads to their immobility and they are often seen to rest at the bottom of their tank.

It is best to keep a single betta fish in a tank as it is the ideal environment for healthy fish to move around, explore, and thrive.

However, if you want to introduce other fish into the tank, it is important to make sure that the tank is at least 10 gallons, and has plenty of vegetation and places to hide.

There are a few tank companions that are not advisable to be kept alongside bettas. First, you should not keep two betta fish together because they tend to become very aggressive. Two male bettas should especially not be kept together.

It is also recommended that you do not add other bright-colored fish with long flowy fins as the betta fish tend to nibble on the fins of other fish.

Freshwater snails and ghost shrimps are the best tank mates for betta fish. When it comes to fish, Cardinal Tetras, Harlequin Rasboras, Corydoras, Neon Tetras, Bristlenose Plecos, Ottocynclis, Kuhli Loaches, Mollies, and Rummynose Tetras are the best tank mates to have.

fish staying at bottom of tank


What Causes a Betta Fish to Lie on Its Side?

A betta fish laying on its side can be a cause for multiple reasons. The fish might be sleeping on its side or it might be a case of constipation or swim bladder disease.

What Causes Them to Lay at the Bottom of the Tank Upside Down?

Swim bladder disease is one of the most common illnesses among betta fish and it often causes the fish to lie at the bottom of the tank upside down.

What If They’re at the Bottom of the Tank Breathing Heavily?

Hot temperature, ammonia poisoning, or nitrate poisoning are the possible reasons why you find your betta fish laying on bottom of tank and breathing heavily. In this case, it is recommended that you take immediate action.

What Fish Can Coexist with Bettas?

When it comes to fish, Cardinal Tetras, Harlequin Rasboras, Corydoras, Neon Tetras, Bristlenose Plecos, Ottocynclis, Kuhli Loaches, Mollies, and Rummynose Tetras are the best tank mates to have.

Is It Normal for a Betta Fish to Stay Still?

Betta fish lays still in some cases and it is completely normal. This is when the fish is sleeping, resting, taking a nap, or has reached old age.

What Are the Differences Between a Sleeping and Dying Fish?

The key difference between a sleeping and dying fish is that you will see slow movement of the gills and steady breathing in the case of a sleeping betta fish.

There is no movement in a dying fish, and you might often find it at the surface of the water or bottom of the tank. Dying betta fish are also slow responders.

fish at the bottom of tank


As we have seen, although it might cause pet owners some amount of stress when they see their betta fish laying on bottom of tank, this does not always mean your fish is dying. There might not even be anything wrong with the fish, to begin with.

In other cases, it can sometimes be an early warning sign of a serious illness or poisoning. Always rule out such issues before assuming everything is fine or something is wrong.

Cody Mitchell
Cody Mitchell is a pet lover and a passionate pet writer. He has worked as a professional writer for over 6 years, with a focus on creating compelling content for pet-related brands. His work has been featured in major publications. When he's not writing, Cody can be found playing with his two dogs (a labradoodle and a cocker spaniel) or cuddling his cat.

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