Why is My Betta Fish Floating on its Side

Why is My Betta Fish Floating on its Side?

Why is My Betta Fish Floating on its Side

One day, you walk by your betta’s tank to feed your little friend, and his swimming seems a bit off. The next day you walk by, and he’s stuck at the top of the tank, unable to swim down. A day later, he looks sadder than ever, stuck on his side at the top of the tank. What’s happening to him?

If your fish is stuck at the top of the aquarium and unable to swim down, they are suffering from swim bladder disorder. This disorder is just a general name for any condition that affects the swim bladder. The swim bladder is essential for swimming, so it needs to be fixed as soon as possible.

In this article, we will cover the swim bladder, swim bladder disorder, parameters, diet, other causes, treatment, and dropsy.

Swim Bladder

Fish have many specialized organs that we do not have. For example, fish possess an organ called a swim bladder which allows them to regulate their buoyancy by letting air in and out of this organ.

In most fish, this organ has two sections. One is in the front of the body behind the head and the other is by the tail. The front portion is much more secure and rigid than the back portion, while the back portion can move out of place and become damaged more easily.

The swim bladder allows a fish to control their position in the water. For example, if they want to go downwards in the water, they let air out of the swim bladder. If they want to go up, the take in more air.

This process allows them to combat the crushing pressure of the water above them and easily move through it. Of course, the swim bladder doesn’t control their movements, but fish are unable to swim properly without them.

Swim Bladder Disorder

When describing general issues with the swim bladder, the terms swim bladder disorder and swim bladder disease are most commonly used. These most often present with a floating fish, whether it floats upright, upside down, or on its side. A sinking fish is also indicative of a swim bladder issue.

Fish need their swim bladders to function properly, so you will be able to easily tell if there is an issue with your fish. In bettas, this is a very common condition. Luckily, it is easily treatable.


Most notably, incorrect parameters, namely temperature, cause swim bladder issues. In addition, if you have any ammonia or nitrite in your tank, they will burn your fish and make it difficult for your betta to breathe. This causes constant stress and will weaken the immune system.

If the nitrates are over 20ppm or the temperature is below 78 or above 83, these are also major issues that need to be addressed. Water changes will get rid of ammonia, nitrite and nitrate. If the temperature is too cold, you will need to get another heater or a higher wattage heater.

When the temperature is too cold, a betta’s metabolism works much slower than it should which can lead to constipation. Therefore, the fish will not be able to digest food as quickly and efficiently as it should, which leads to some backup.

Furthermore, stress and injury from ammonia, nitrite, and nitrate poisoning can cause the swim bladder to work less effectively or even shift. In addition, it leaves your fish susceptible to bacterial infections of the swim bladder and other organs. This means your fish will not be able to control its movement up and down as well as it should.


The diet is a very common cause of swim bladder problems. If the fish eats too much fat, too little protein, too little fiber, too much vegetable matter, etc., then they will become constipated. As a result, this constipation will put pressure on the swim bladder and could cause it to be less effective.

On the other hand, the constipation could cause your fish to produce excess gas that the swim bladder cannot deal with. Either way, both scenarios would cause your little friend to get stuck at the top of the aquarium.

When it comes to bettas, overfeeding freeze-dried bloodworms can often lead to bloat and constipation. Bloodworms are meant to be a supplement to a betta’s diet, but they are high in fat and difficult to digest. The process of freeze drying takes out most nutrients and causes it to expand significantly in the digestive tract. Both easily cause constipation and bloating.

Your betta should only eat bloodworms 1-2 times a week, and it’s better to feed frozen ones. That way, your fish gets some kind of nutritional value instead of it just being turned into excess waste.

Constipation can also arise from overfeeding. Ensure that you are feeding your fish an amount of food the same size as its eye 2-3 times a day.

Additionally, pellets and flakes expand once they hit the water. In other words, you should see how far they expand in order to judge how much you should feed your fish.

For example, some keepers have issues feeding their bettas pellets if they are left to expand in their digestive tract. It is much healthier to feed your betta pellets that you have left to soak. In other words, this means your betta won’t have any digestive discomfort.

Other Causes

As previously mentioned, incorrect parameters and/or an incorrect diet are the two primary causes of swim bladder issues. However, there are many other potential causes which range from birth defects to cancers.

Bettas, like every other animal, are not immune to tumors or cancers; in fact, they are prone to tumors, but these are most often non-cancerous and will not metastasize. Normally, these do not cause major issues, but if a tumor forms on the inside of the fish, especially along the digestive tract or the kidneys, it could move the swim bladder. In turn, this movement of the swim bladder can result in issues with buoyancy.

It is also possible for bettas to suffer from an intestinal disease that produces excess gas. As a result, the gas produced may be too much for the swim bladder to counteract, causing the fish to float. In this type of swim bladder disorder, it is more likely that your fish will float belly up, rather than just on its side.

Additionally, in terms of swim bladder conditions that cause your betta to sink, the possibilities are widespread. Tumors, cancers, and digestive issues can also cause sinking. These digestive issues generally include the fish eating something they shouldn’t.

For example, if your betta swallows some gravel or sand, that can wind up in the intestines and weigh the fish down. The piece(s) of substrate may be too heavy for the swim bladder to counteract. Therefore, your fish will end up spending much more time at the bottom of the tank.

Another cause of your fish sinking is fluid in the swim bladder. Injuries and bacterial infections can cause this, but these cases are luckily rather rare.


The treatment for swim bladder depends on the condition. For example, if the cause is an internal tumor, there is often nothing you can do. However, it is impossible to diagnose this without the help of a vet, so that same vet may be able to do a surgery on your fish, but it is often too risky.

For example, treating common causes of swim bladder disorder include changes to the diet, water change schedule, and the addition of Epsom salt to clear up the issue. On the other hand, if you were feeding a diet that was too fatty, lacked the proper amount of fiber, or lacked enough protein, a food change will help. Click here to see food products

Also, if you feed your fish a staple food plus some frozen food, such as Mysis shrimp, brine shrimp, daphnia, and blackworms, your fish’s digestive tract will thank you. This is because these foods are much easier for your fish to digest.

Before changing the diet, you should fast your fish for 2-3 days, feed frozen daphnia for one day, then resume feeding. Frozen daphnia is great at clearing bloat and constipation in bettas and is high in protein.

If your temperature was too low, you should also fast your fish and feed daphnia before resuming a normal feeding schedule. The fish’s metabolism needs some time to adapt to the warmer water and increased speed.

However, if these tricks didn’t work, dissolve Epsom salt in a separate container of water. Dissolve 1 tbsp for every 5 gallons of water in your betta’s tank. Over 10-15 minutes, slowly pour it in your betta’s tank. Epsom salt helps reduce bloat and constipation as well, so with fasting and Epsom salt combined, your betta will be back to its old self in no time.


In this section, we will discuss a potential issue that you may misidentify as swim bladder disorder; dropsy. In other words, dropsy is kidney failure and can have similar symptoms to or even cause swim bladder disorder. A fish’s kidney doesn’t only filter the blood; they also filter fluid in and out of the body. When this function is interrupted, your fish often swells and fills with fluid, which can cause it to float or sink.

Dropsy is nearly impossible to cure, and many elect to humanely euthanize the fish when they get this condition. The primary symptom is a fish swollen at every area, not just the stomach, with scales “pine coning” out of the body.

This pine coning is easily identifiable, as the scales stick outward all over the body. This is due to fluid buildup in the scales themselves, forcing them out. It is likely that the eyes will also be bulging in the fish, which is not often associated with swim bladder issues. That being said, if swim bladder problems are caused by improper water parameters, pop eye is also likely to arise in the fish.

For Dropsy treatment, you need to add Epsom salt to the water. The dose is the same amount used to treat bloating and swim bladder disorders. You will also need Kanaplex. The kidney failure most commonly seen in aquariums is caused by bacteria, and Kanaplex is an antibacterial capable of treating Dropsy.

In conclusion, swim bladder disorder is a common condition when it comes to bettas. They often have severe digestive issues if fed the wrong food or kept in improper water conditions. Thankfully, in most cases, the condition is easily treatable and causes no lasting damage to your fish.

Leave a Comment