Seeing your Betta fish laying on side is a common phenomenon in many fish tanks and aquariums. It is always an alarming condition that we need to be aware of as aquarists.

But if you think that there might be some underlying reasons behind your fish’s condition, then don’t get worried. It’s just time to educate yourself, and this article will help you with that.

Why Is My Betta Fish Laying on Its Side?

Unlike many other aquarium fish, Betta fish are not fast swimmers. But that does not make them lazy or inactive. They will roam around in the aquarium for almost the whole day since Betta fish like to explore their surroundings in the aquariums. And at times, they will take rest as well.

It is unnatural and unhealthy for a Betta fish to lay down on its side at the bottom of the tank. However, if it is for just a few times in a day and not so long, you can ignore this. This does not indicate any discomfort or health issue of your Betta fish. But, if this is a persistent behavior of your Betta fish, this is alarming, and it’s time for you to be extra careful about your fish’s gut and aquarium environment.

There might be a variety of reasons why your Betta fish is lying down on one side other than simply relaxing, sleeping, or napping. Some major reasons are exhaustion and lethargy, problems in digestion, breathing, swimming, inappropriate tank water flow, and fin loss.

To further know about these issues that your Betta fish might be dealing with, you need to give a read to the next few points.

– Nitrate Imbalance in Water

10-20 ppm (parts per million) is the ideal concentration of nitrate in your Betta fish tank. But in case you have some sick Betta fish in the aquarium, this level should be lower than ten ppm. When it comes to this concentration of nitrate, it is a little bit tricky to handle since many living plants in the aquarium live off nitrate.

You will need these living plants to maintain the holistic ecosystem of your aquarium. You have to be careful that the concentration does not, in any way, cross the ideal limit of 20 ppm. It would help if you remembered that too much nitrate is toxic for your Betta fish.

– Too Strong Water Current of the Fish Tank

A significantly strong water current is not suitable for Betta fish. Since Betta fish are naturally slow swimmers, strong water current may cause hindrance to the natural swimming speed of your Betta fish. Also, it might happen that your fish will fail to swim up against the current. When betta faces this kind of disturbance for a long time, it gradually and slowly loses all its energy to swim.

– Swim Bladder Disorder

Even though not a lethal disease, Swim bladder disorder causes much discomfort to the Betta fish. The reasons include, but are not limited to, overeating, constipation, and swelling up of the stomach. Their bladder narrows due to overeating. Betta fish feel heavy on the stomach and thus uncomfortable moving around. So you find your Betta fish to lay down at the bottom of the fish tank.

By many professionals, swim bladder disorder, in and of itself, is not any disorder. It is just an imbalance in buoyancy that results in your Betta fish not swimming. There are both positive and negative buoyancy problems. But negative buoyancy is the cause behind your Betta fish not moving. Infections, poor water quality and diet, and digestion issues mainly cause this type of imbalance underneath the water. Sometimes, poor genetics can also play a role here.

A more severe case is when water enters into the fish’s swim bladder, making it extremely difficult to inhale and exhale. This is quite a risky state, and it might even cause the death of the fish.

– Constipation

Closely observe the diet of your Betta fish. Are you giving it only or mainly fish flakes and freeze-dried food? Then it is high time you changed your diet. Too much of these foods can cause constipation to your bettas.

The problem with these foods is that they start to expand as soon as they come in contact with moisture. And as such, they might feel pain or discomfort in the stomach. This, in turn, results in your Betta fish floating on side or simply laying down.

– Inappropriate Water Temperature Of the Fish Tank

The other reason behind your betta laying on side might be the temperature of your fish tank. Bettas are tropical fish, meaning they need warm water to survive and grow. The ideal temperature is somewhere between 75 F to 86 F. If your fish tank has a temperature too high or too low than the ideal one, then it may cause discomfort to your Betta fish.

Temperature less than 75 F is not ideal for the digestion of food. It slows down the metabolism process. Delayed metabolism causes lethargy in bettas. And so, they are found laying down on the side or bottom of the fish tank.

On the flip side, too much warm environment causes an excess and frequent release of oxygen. This results in the gasping of Betta fish. Too much gasping is not a healthy phenomenon for the bettas.

– A Lower Level Of Oxygen

Even though Betta fish have a special organ named the labyrinth, which helps them take oxygen from the air, unlike many aquarium fish, the continuous low level of oxygen in the fish tank causes severe problems to the Betta fish. It makes them lethargic and unable to swim.

– High Ammonia Level In-Tank Water

Too much ammonia in the water is toxic for the bettas and poses a harmful threat to their lives. High ammonia levels might result from excessive waste from the living water plants and other beneficial bacterias. Other than that, overfeeding can also result in increased ammonia levels since food waste turns to ammonia.

– Small-Sized Fish Tank

In any natural habitat, Betta fish get multiple times more space than your artificial fish tank. Your target will be to make your tank as much as its natural habitat. Betta fish will require a minimum of a 3-gallon tank. The thumb rule here is to have one gallon of water for every inch of fully grown Betta fish.

Too small of a fish tank will take away the natural energy of the bettas to swim around and explore their surroundings. And you will find your fish laying on the bottom of tank. Also, the water quality degrades quickly in a small spaced tank. This is quite toxic to Betta fish’s health.

Another downside of having a small-sized fish tank is that Betta fish like to hide. When they don’t find enough space to hide themselves up, they go down at the bottom of the tank.

– Old Age

The average life cycle of Betta fish is three years. If your Betta fish happens to be somewhere around that age, you may find your fish laying on side of the tank. This is because their energy level drops with age like any other fish.

– Lethargy

Lethargy in Betta fish is often the result of temperature issues in the tank water, low metabolism rates, or eye issues. It is not necessarily an indication of any crucial disease, yet it is better to check certain common diseases of the bettas if you notice significant and constant exhaustion. These diseases include but are not limited to fungal infection, ich, velvet, sores, bulging eyes, pop-eyes, and dropsy.

– Lack of Enough Plants and Hiding Spaces

Living plants and other fish create a holistic environment for Betta fish to live in the fish tank. This also helps to maintain the ecosystem of the tank water. Lack of plants and other fish create an imbalance for the bettas.

Besides, living plants also provide Betta fish with more opportunities to hide. In the absence of that, Betta fish choose to lay down on the bottom of the tank.

Steps To Cure Your Betta Fish Laying on the Side

– Checking on the Chemical Levels

You have to regularly keep an eye on the levels of different chemicals like ammonia, nitrate in your tank water. Buy yourself a good quality chemical checker to avoid faulty reading.

If the levels read alarmingly high, indicating a toxic environment for your Betta fish, then you have to remove the nitrate and ammonia. Care should be taken so that the process is not very fast. Instead, it should be done in a controlled manner since too quickly in the change process might give a shock to your Betta fish.

Oxygen levels should also be observed regularly since too much and too little oxygen are harmful to your bettas’ healthy growth.

Maintenance of the Tank

Tank water should be cleaned at least once a week. This helps to get rid of the built-up toxins in the water. Additionally, this also makes sure that your fish tank is visually appealing. Dechlorinated water of perfect temperature needs to be added after every cleanup.

– Treating the Swim Bladder Disorder

If you are concerned with your sick Betta fish, you first need to treat its swim bladder disorder. The reason is, treating this particular illness can easily ensure that your Betta fish will not develop any similar kind of disease.

Making your fish fast for about a day or even more assessing the situation can easily clean up their digestive channel. This helps in treating bladder disorders. Also, make sure that you are giving enough fibers. Some aquarists prefer to give Daphnia, which is a good source of fiber and readily available. You can also give it a try.

– Adding Fibers To the Diet

Plenty of fibers is needed to avoid constipation. Some foods swell up once taken by the fish. This creates much disturbance in the fish’s stomach and also a feeling of indigestion and bloating. To avoid bloating, you can soak your fish food in aquarium water or dechlorinated water. This allows the food to swell first outside your fish’s body.

– Minimizing the Water Current

Betta fish have got relatively bigger and oversized fins. As such, it is a slow swimmer. But when added to its oversized fins, it becomes difficult for them to swim. So, it is recommended that you turn down the water current.

When planning for keeping Betta fish in your fish tank, buy the tanks having water flow controlling valves or an inbuilt filter in them. If you already have a fish tank with no adjustable valves, then go for some DIYs.

Strapping a bag in the mouth of the water source is an easy solution to this problem. Other than that, you can make some small holes in the water pipe to disperse the water flow. Keeping the water pipe long can also reduce the water current.

If you want to keep the aesthetic of your fish tank intact, try using some live plants or stones, or other decorations in the opening mouth of the water source. This will act as a barrier to the water flow.

– Warming Up the Water Inside

Most aquarists use an artificial heater to maintain the optimum temperature inside the fish tank. Especially when you have Betta fish, you need to be extra careful about the water temperature.

Other than that, keeping the fish tank in a sunny area is advisable. However, if you plan to keep it in a place filled with artificial lights, make sure that the lights are not always turned on since this may disrupt the sleep cycle of the fish and result in lethargy.

Transferring your fish tank to a relatively warm place or near the heater can be a temporary solution. You can also turn up the heater of the room, if any. And finally, while changing water, make sure you are using warm water.

Using lights can make the fish water warm as well. But here to note that most aquarists use LEDs since these are cheap and easily available. The problem with LEDs is that they do not emit any heat. So, look for alternate lights if you plan to warm up the water through the aquarium’s light sources.

It should be noted that sometimes your fish tanks are placed in scorching areas. In that case, precautions should be taken to reduce the temperature. You can use a fan to regulate the temperature. A costly alternative would be to air-condition the room.

But always remember that any change in the water temperature should be brought gradually. Otherwise, this gives a sudden shock to the Betta fish.

– Installing an Automatic Feeder

An automatic feeder is an easy solution to the overfeeding problem. Since overfeeding further leads to many problems, installing a feeder can help your fish. An automatic feeder ensures that your Betta fish are fed just the right amount.

– Proper Tank Cycling

Before introducing Betta fish to your fish tank, make sure that the tank is fully cycled, either naturally or artificially. The natural cycling process takes a bit of time, which is about a month. If you wish, you can also go with the artificial processes like adding a filter or using the tank water of an already established and cycled fish tank.

Proper cycling ensures that there are enough beneficial bacteria in the tank water. Cycling is a process of introducing beneficial bacterias in fish water. These bacterias break down the ammonia into nitrate. And nitrate is considered to be less harmful compared to your fish to ammonia.

It is recommended that you change your tank water every two weeks. Your aim should be to remove 10 to 25 percent tank water and replace it with fresh dechlorinated water.

After every cycling, measure the chemical levels in the tank water. Always remember that, if done correctly and fully, a cycled tank water has 0 ppm of ammonia, 0 ppm of nitrite, and somewhere near 10 ppm of nitrate.

– Large Tank

Betta fish can live off healthily if a larger tank is provided. Often it is seen that due to lack of enough space, Betta fish have to lay on the side of their uneaten food or their own bodily waste. This, if it continues for a long time, might develop fungal infections and other diseases.


Keeping your Betta fish healthy in your fish tank is not that much of a hard task. If you have gone through this entire article, you now have some insights into how to do that. Let’s remind you one last time what are the dos and don’ts:

  • Cycle your fish tank regularly to keep it clean, residue-free, and liveable for your Betta fish.
  • Maintain the water temperature and keep it between 75 F to 86 F.
  • Feed your bettas more fibrous food to avoid constipation. And do not overfeed.
  • Ensure a healthy and moderate flow of water current.

Also, remember that the act of laying down doesn’t always indicate that something is wrong with your Betta fish. It might just mean that your aquatic friend is simply relaxing or napping.

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