Betta Fish Swimming Vertically: Reasons & How to Solve it

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The more I got into betta fish; the more odd behaviors caught my attention. For example, more than once, I’ve noticed that my betta swims vertically, up and down the tank. To determine whether it was sick, I began to investigate the topic pretty extensively.

Betta fish typically swim vertically due to an underlying ailment, such as swim bladder disease, constipation, and infections. That also happens when the water conditions are poor or if the tank is too small. Nevertheless, up and down swimming in bettas could merely be a matter of personality.

As we move forward, I will teach you how to distinguish normal behavior from an underlying ailment. I will also share a few useful techniques to treat constipation and swim bladder disease, which may be the most severe cases.

Also Read: Betta Fish Diseases

Why Is My Betta Fish Swimming Vertically?

Because betta fish cannot talk, you have to observe their behavior to measure their mood and health. The manifestation of abnormal behavior typically means that something has gone wrong.

Vertical swimming is usually abnormal behavior. Bettas are not supposed to swim up and down. And if your bettas are swimming this way, you have to identify the reason. That is the only way to craft an effective solution. Some common causes of erratic swimming of this sort in bettas include:

1. Personality

Betta fish are odd creatures. You cannot always predict their personalities. Not every betta that swims up and down the tank is distressed. For some fish, this behavior is perfectly normal, especially if it isn’t regular. It shouldn’t worry you unless additional signs of trouble accompany it.

You should carefully observe your betta fish’s appearance to ultimately determine that it swims that way due to personality reasons. If your betta also seems sluggish and bloated, for example, you should take its swimming behavior seriously.

2. Swim Bladder Disease

If your betta is swimming erratically, swim bladder disease should be your first consideration. That is because the illness is associated with the gas-filled sac that affects the fish’s balance in the water.

Whenever the swim bladder is injured or assaulted by a disease, the betta’s ability to swim deteriorates. That is because the trapped gas forces the fish to float. Therefore, any erratic swimming on the part of a fish should raise questions about the swim bladder.

If your betta is swimming vertically, look for signs of swelling around the stomach, not to mention lethargy, and a crooked posture. Inadequate water conditions, infections, constipation, and injury can cause swim bladder disease. But it isn’t contagious.

Also Read: Why Is My Betta Fish Upside Down?

3. Constipation

Constipation can occur as a result of an inappropriate diet or overfeeding. The illness doesn’t sound that serious, but it is more than capable of debilitating your betta’s ability to swim, leading to abnormal behavior such as vertical swimming.

If your betta is constipated, it will produce stringy feces that will hang from it rather than falling to the bottom.[1] Constipation only affects a betta’s ability to swim when it has become severe. The fish will also become lethargic.

4. Small Tank Size

Like most fish, bettas do not like small tanks. They need at least 5 gallons to swim correctly.[2] Small tanks and bowls are going to induce stress. And stressed fish tend to exhibit abnormal behavior such as swimming up and down the tank.

Some fish are merely looking for a way out. They want to escape their confinement, but they cannot identify a way out. If you fail to remedy their situation, the betta could develop more severe symptoms such as loss in appetite.

5. Poor Water Conditions

Betta fish cannot live in dirty, poorly maintained tanks. They need temperatures ranging between 75 degrees F and 80 degrees F and a pH of 7.0.[3] The water can’t be too hot or too cold. If the temperature changes drastically, the shock could kill the fish. 

You must keep the ammonia and nitrite levels at 0. Also, the nitrates should be less than 20 ppm. You cannot allow the ammonia to accumulate. If it does, it will hurt the bettas, burning their gills, making them sick, and ultimately killing them. But before they die, they will manifest their discomfort through actions such as swimming vertically.

That is one of the reasons why you cannot keep a betta in a small tank. If you do, toxic elements like ammonia might build up too quickly. The same goes for overfeeding; an abundance of food leads to an abundance of waste. That, in turn, contributes to the ammonia concentration in the water.

6. Overstocking

Overstocking is another potential cause of ammonia build-up. The more fish you have, the more food they eat, the more waste they produce. Besides ammonia, you also have oxygen deficiency to consider. 

A tank that is overrun with bettas cannot replenish its oxygen fast enough to meet its inhabitants’ needs. Along with constraining the betta’s freedom and encouraging algae and pest snail infestations, the distress caused by all these factors can lead to vertical swimming in bettas.

7. Tankmates

Bettas are aggressive fish. They have a reputation for fighting. As such, your choice of tankmates is essential. You must pair them with peaceful species that are not known for nipping at other fish fins. Otherwise, a hostile environment in the tank will induce stress in your betta. Stress can cause glass surfing.

By all means, you should avoid companions that swim swiftly and might nibble on your betta’s fins. That is why cichlids and mollies are a terrible choice. You should also avoid putting more than one male betta fish in the same tank.

How to Treat Bettas that Swim Up and Down?

Once you identify the cause of your betta’s erratic swimming behavior, finding a solution isn’t that difficult:

1. Constipation Treatment

If your betta is bloated because of constipation, give it meals that are rich in fiber. Items like peas act as a laxative. The same is valid for brine shrimp. During this period, you shouldn’t give the fish any other food; fasting is a treatment on its own.

If you’ve noticed a bloated abdomen besides the vertical swimming, you should act quickly. Constipation in fish could be fatal if not treated properly. I’ve attached a Youtube video above that will take you step-by-step to solve that issue.

2. Ensure Proper Water Conditions

It is never too late to improve the water conditions in your tank. First of all, you must install a filter. Filters keep the water clean by removing contaminants. Secondly, you must test the water regularly. I personally use the API Aquarium Test Kit (link to Amazon). While relatively cheap, that kit ensures that toxins like ammonia, nitrates, and nitrites don’t exceed the relevant threshold.

Ammonia, for instance, must remain at 0. If you detect ammonia in the tank, you must take immediate steps to eliminate it. Ammonia won’t present much of a challenge if you make regular water changes. That is the easiest way to keep the tank clean. A filter cannot replace regular water changes. 

It would be best if you also vacuumed the substrate. All the food that goes uneaten falls to the bottom along with the waste. If you fail to clean the substrate, the waste and leftovers will rot, adding toxins to the tank. Small tanks will complicate the process of keeping your aquarium clean.

The toxins accumulate too quickly. A bigger tank will dilute some of the chemicals, making it that much easier to maintain the tank.

Of course, none of that will matter if you have too many fish. You need one inch of fish for every gallon of water. Don’t overstock the tank. The waste the bettas produce will destroy the stability of your aquarium.

3. Keep the Temperature Stable

If the weather in your region is problematic and the summer heat keeps causing temperatures in the tank to spike, add a cooling fan. It will control the temperature by blowing across the surface of the water. You can take more drastic steps, such as adding ice cubes in a zip-close bag if the situation becomes dire.

Use a thermostat to test the water temperature every so often. Install a heater if you don’t have one. That will keep the water from falling below the required temperature threshold.

4. Avoid Overfeeding

Bettas have tiny stomachs. You cannot afford to overfeed them. Please give them a maximum of two meals each day. You should also assign one day of the week to fast. That will reduce the risk of diseases like constipation and swim bladder disorder.

If you wish to keep the feeding burden out of your head, I highly recommend considering the Eheim Automatic Feeding Unit (link to Amazon). That device allows me to feed my bettas with the precise amounts that I set, even when I’m out for vacation.

5. Add a Few Plants

Plants and decorations are the perfect answer to a stressed fish. Bettas will use them to hide from predators. The privacy they offer will also put the bettas at ease regardless of whether their tank has aggressive fish.

That might treat the personality case I’ve discussed earlier. If your betta fish gets scared easily, several plants may be all you need. That will allow the fish to hide once it sees your shadow or its reflection.[4]

How to Treat Swim Bladder Disease in Betta Fish?

Treating swim bladder disease in betta fish involves these steps:

  1. Stop feeding your bettas for three days and raise the temperature by 2-3 degrees F.
  2. Use a bacterial infection remedy such as Melafix.
  3. Add one tablespoon of Epsom for each gallon of water.
  4. Place an aquarium divider to avoid aggression and conflicts from other fish.

1. Feeding Habits

If overfeeding was the cause of this ailment, don’t feed the betta for three days.[5] You should also raise the temperature by a few degrees. The objective is to raise the rate at which the betta digests food.

If this doesn’t produce results, give the betta cooked, peeled peas. As was noted above, they act a laxative. Maintain this diet for a week. It will clear the obstruction in the betta’s stomach.

2. Infection

If an infection (bacterial or parasitic) is responsible for your betta’s swim bladder disease, move it to a separate tank. The objective is to dose the water with medicine without affecting the other fish. Otherwise, your whole tank might be in danger.

Parasites, like myxozoan, might infect your fish and be responsible for the swim bladder disease.[6] Typically, they respond to products like Betamax.[7] In the case of bacterial infection, I highly recommend checking the API MELAFIX (link to Amazon). However, if you have doubts about either drug, talk to a vet. They will guide you accordingly.

Also Read: Betta Fish Rubbing

3. Shock

If shock and stress are to blame for the disease, possibly resulting from an injury or drastic shifts in temperature, there is no immediate solution for you to deploy. You have to give the betta time to recover on its own. You can aid the creature’s recovery by switching the lights off and making sure that all other tank conditions are optimal. That will encourage the betta to rest.

If all other solutions fail, try a salt bath. That involves adding Epsom salt (one tablespoon) to half a gallon of conditioned tap water, waiting for the salt to dissolve, and then adding half a gallon of aquarium water to the mixture (before submerging the betta for 15 minutes).

Of course, it is easier to prevent swim bladder disease than to treat it. You can do this by feeding your betta only the highest quality food and in the right amounts. You should also maintain a clean tank (free of contaminants and toxins), and prevent unnecessary conflicts by either inserting a divider or removing the fish that keep clashing with your bettas.


If your betta is swimming vertically, up and down the tank, it should raise a question. To make sure that your betta is healthy and merely swims that way due to its personality, you should look for additional signs.

If besides that behavior, everything seems okay, you should probably ignore that issue. However, if your fish also appears bloated, sluggish, or pale, you need to take action. Start by testing your water for ammonia and nitrites. You should also isolate the sick fish and treat them, as mentioned above.