Why Is Betta Fish Swimming Erratically?

There are various reasons why your betta fish may be swimming erratically, ranging from nervous system disorders to poor vision.

While some erratic swimming results in conditions that aren’t life-threatening, many others are.

We’re here to help you determine why your betta fish is swimming irregularly and support you with finding solutions.

Reasons a Betta Fish Swims Erratically

The reason your betta fish is swimming erratically may or may not be within your control.

Below are some of the most common causes of swimming irregularities.


Parasites are a common condition in bettas. Thankfully, they’re an easy problem to resolve in most cases.

Bettas often swim erratically when they have parasites to rub off the parasites on different objects.

You’ll want to start by moving your betta to a quarantine tank if it shares a home with other fish.

Then, use a parasite treatment, which you can purchase from your local pet store.

Parasites that commonly cause betta fish to swim erratically include anchor worms, ich, and gill flukes.

You should see improvements with your betta’s swimming within days of using medication.


Hypoxia is a condition resulting in low oxygen in a betta’s blood.

If your fish is experiencing hypoxia, it’s likely hovering at the top of the water, trying to seek more oxygen.

Maintaining a comfortable water temperature is critical to preventing hypoxia.

If the water is too warm, you could inadvertently create this unwanted disease in your betta fish.

While hypoxia is often due to little oxygen, it can also result from gill disease or anemia.

These conditions will also make your fish swim erratically.

Swim Bladder

Although people often call it a disease, swim bladder is a general term for various issues involving a betta’s swim bladder.

As you can imagine, issues with a fish’s swim bladder impact its movements.

Betta fish experience many similar issues that humans do, such as constipation, congenital disabilities, and bacterial infections.

All of these can alter how your betta fish swims.

Unlike parasites, swim bladder is more difficult to detect.

Nervous System Disorders

Yes, your betta fish has a nervous system too. Congenital disabilities are a common cause of nervous system disorders.

Neurological damage from aggressive fish or encounters with sharp objects in the fish tank can also impact the nervous system.

Additionally, bacterial diseases like tuberculosis and damage from parasites can create neurological damage.

A classic sign of nervous system disorders is when bettas swim in circle patterns.

Unhealthy Diet

Unlike the goldfish you may have sitting in a bowl beside your bed, betta fish are strictly carnivores.

As a result, they require a diet high in protein.

If your betta doesn’t receive sufficient protein and other nutrients, it will affect its swimming abilities.

Weakness and constipation are also symptoms of a poor diet.

When choosing food for your betta fish, dried, frozen, or fresh insects and larvae are ideal.

If these aren’t feasible for you, betta pellets offer solid nutrition.

Bad Eyesight

Just like people, a betta fish’s eyesight can deteriorate as they get older. Bettas can live up to four years, although the range is typically two to four years.

Therefore, once your betta turns around three years old, poor eyesight due to age may be normal.

Nevertheless, there are other more concerning causes of poor vision, including parasites and conditions like popeye.

Issues With Tank Water

Your betta fish’s external environment is just as important to keep it swimming well as the food it consumes.

Poor water quality is detrimental to bettas and can create erratic swimming.

You should take the following precautions if you see your betta fish swimming strangely:

  • Check your water’s pH level. It should be around 7.
  • Ensure there isn’t lots of ammonia in the water, as it can cause ammonia poisoning.
  • Avoid any situations that could result in extreme temperature changes.

How to Tell If Your Betta Is Swimming Erratically

If you just brought your betta fish home, it’s understandable if you feel confused about whether it’s swimming correctly.

In fact, many betta fish have odd swimming behaviors when they arrive in a new tank (which can be perfectly normal behavior).

Below are some of the most common signs that your betta is swimming unnaturally:

  • Floating on top of the water
  • Swimming in circles
  • Floating upside down
  • Banging into objects (plants or decorations)
  • Rubbing against objects
  • Twirling without a straight path

Now we’ll look at what could be causing these behaviors and how to treat them.

Treatments for Erratic Betta Fish Swimming

Your local veterinarian will likely give you a funny look if you bring them a betta fish with irregular swimming issues.

So, you’re most likely on your own to treat your fish’s condition.

Below are some of the best ways to cure different kinds of erratic swimming or, at the very least, make your betta fish more comfortable.

Swimming in Circles

Swimming in circles isn’t necessarily erratic behavior for betta fish.

For example, they might do this when they see their reflection, are new to a tank, or from not have enough space.

As a result, it’s one of the most common forms of irregular swimming in betta fish.

Sometimes it takes a bit of creativity to determine why your fish is swimming in circles.

For example, did you use a new cleaning product on or near the tank? How about air fresheners?

Betta fish are sensitive, so if any such chemicals make their way into the tank, they may react by swimming strangely.

Treatments include:

  • Only turning on your aquarium light in the daylight or pasting background wallpaper to the tank. That way, you’ll decrease reflections.
  • Move your betta to a bigger tank.
  • Stop using any new chemicals, as this may be throwing off your fish.

Brain trauma is another reason that bettas swim in circles.

However, unless you witnessed your fish smashing into an object in the tank, it’s unlikely you’ll know that’s what’s causing the issue.

Upside Down and Twirling Swimming Pattern

In almost all cases, betta fish that swim upside down or twirl around have swim bladder disease.

The good news is that the swim bladder rarely kills fish.

More often than not, swim bladder disease results from constipation.

Issues with bowel movements are common if you feed your betta a lot of frozen food or dry pellets.

These foods are good for your fish, so we don’t recommend removing them from your diet permanently.

However, we’ll share some strategies you can use to prevent constipation from happening.

Treatments include:

  • Halt feedings for one to three days. That gives time for food to run through it if it’s constipated.
  • If you use dry pellets or frozen food, drench them in water before giving them to your fish.
  • Offer your fish daphnia, which is packed in nutrients and acts as a laxative.
  • If the strategies above don’t work, try applying antibiotics.

Assuming the antibiotics take care of your betta fish’s swimming problem, then the issue was likely bacteria-related.

Excessive Rubbing

If your betta begins rubbing its body on everything or banging into objects, it’s likely the result of parasites or ammonia poisoning.

Some of the most common parasite species that affect betta fish are anchor worms, velvet, and gill flukes.

Luckily, you can kill most parasites and get rid of high ammonia concentrations.

Treatments include:

  • Anti-parasite medicine or aquarium salt if you believe that parasites are the cause.
  • Change the water in 25% increments every day.
  • Find out if the water has a high ammonia concentration by using a test kit.

Swimming at the Surface

Don’t panic if you see your betta fish at the top of its tank sometimes—that’s where it goes to get oxygen.

However, if your betta is spending most of its time at the top of the tank and seems to be floating listlessly, there’s an issue.

Treatments include:

  • Changing out 75% of the water.
  • Treat the new water with a water conditioner before pouring it into the tank.
  • Purchase live plants for your tank.
  • Check that the filter system is working correctly.
  • Ensure there’s sufficient space between the lid and water so your betta can breathe.

Swimming at the surface can also be a sign of swim bladder disease. Therefore, if these strategies don’t work, try those we covered in the swim bladder treatment section.

When Betta Swimming Erratically Is Okay

Betta fish can get bursts of energy, particularly when they realize you’re about to feed them.

They also might play in the tank or simply show signs of happiness.

All the scenarios above can create a healthy version of erratic swimming.

You know your betta best. It should be easy for you to tell whether its swimming patterns are normal by observing its everyday movements.

Be Your Betta Fish’s Hero

Now that you have more knowledge on erratic betta fish swimming, go ahead and start implementing the strategies we covered here.

Hopefully, your betta fish has one of the many treatable swimming disorders.

They say bettas are intelligent creatures, so don’t be surprised if your fish blows bubbles in thanks as it resumes healthy movement around its tank.

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