Neon Tetra Swim Bladder Disease: Causes, Symptoms & Treatment

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Neon tetras are a beautiful addition to your tank. However, when they start acting strangely, it immediately raises some concerns.

In this article, I will discuss a particular condition known as swim bladder disorder in neon tetra fish. 

You will learn how to identify the ailment, how to treat it properly, and how to prevent it from reoccuring in the future.

Let’s dive right into it.

What Is Swim Bladder Disease?

First and foremost, it is crucial to comprehend what swim bladder disorder entails. Rather than being a single disease, it is more akin to a condition or disorder.

Multiple factors can contribute to the occurrence of swim bladder disorder, and identifying the specific cause is essential for effective treatment.

In essence, swim bladder disorder refers to the impaired functioning of the swim bladder.

Also Read: 17 Neon Tetra Diseases & Their Treatments

What Causes Swim Bladder Disorder In Neon Tetras?

Before initiating any form of treatment for swim bladder disorder, it is important to understand the various causes. Different causes may require distinct approaches to treatment.

Here are the most common ones:

1. Physical Injury

Neon Tetras are small and delicate creatures that can easily suffer physical injuries.

Sudden encounters with other aggressive fish, improper handling during transfer, or collision with sharp and rough decorations in the aquarium can lead to injuries.

This can result in both immediate harm and increased vulnerability to secondary infections. 

When the swim bladder is harmed, it may either rupture or become inflamed, resulting in buoyancy issues.

2. Digestive Issues And Constipation

Like many species, neon tetras can suffer from digestive problems when they are fed an inadequate diet.

This can encompass situations such as overfeeding, where the fish consume an excessive amount of food in one sitting, resulting in bloating.

Additionally, a diet lacking in fiber can lead to constipation.

With the development of these conditions, the enlarged digestive system can compress the adjacent swim bladder, impair its function and lead to symptoms of swim bladder disease.

Also Read: Neon Tetra Constipation

3. Environmental Shock

Fish are sensitive to their environment. Sudden changes in water conditions can create stress, disrupting the body’s normal functions.

This includes changes in water temperature, pH, and salinity that are not introduced gradually.

A fish responding to this type of stress may exhibit a variety of symptoms, including problems with buoyancy due to a stressed or impaired swim bladder.

4. Newborn Fish

Newly hatched or born fish, called fry, are still developing their various organ systems. The swim bladder, among other organs, may not be fully functional immediately after hatching. 

As a result, some fry may experience temporary swim bladder problems until their organ matures and stabilizes.

5. Low Water Temperature

Neon tetras originate in warm, tropical environments and require a consistent, warm water temperature to thrive.

Significant drops in aquarium water temperature can have several effects on fish.

It can cause a slowdown in their metabolism, leading to delayed digestion and potential constipation.

As mentioned earlier, this can put pressure on the swim bladder and cause illness.

6. Parasitic And Bacterial Infections

Parasites and bacteria can invade the swim bladder, leading to inflammation and impairment of function.

This can occur due to factors such as inadequate water quality, the introduction of infected fish, or a compromised immune system.

For example, bacterial infections such as Aeromonas can cause swim bladder disease, while parasites such as nematodes can physically block or damage the organ.

7. Egg Binding

This condition occurs in female fish when eggs remain in the reproductive system and are not expelled normally.

The accumulated eggs can create significant internal pressure, which damages nearby organs, including the swim bladder.

This can cause functional impairment of the swim bladder, leading to buoyancy problems.

8. Other Organ-Related Issues

Diseases or malfunctions affecting nearby organs can also affect the swim bladder.

Kidney diseases can lead to fluid accumulation in the body cavity, putting pressure on the swim bladder.

Liver disease can alter the buoyancy of the fish by changing the total fat content of the body. 

Specific intestinal diseases can induce bloating and constipation, which, as we are aware, can directly impact the swim bladder.

What Are The Symptoms Of Swim Bladder Disorder In Neon Tetras?

The symptoms of swim bladder disorder in neon tetras are relatively easy to detect. Pay attention to the following signs if you suspect your neon tetra has the disorder:

1. Buoyancy Problems And Difficulty Swimming

The swim bladder is a gas-filled organ that allows fish to control their buoyancy and navigate through different depths of water.

When the swim bladder is diseased or damaged, this function can be disrupted, leading to problems with buoyancy.

Neon Tetras may struggle to maintain a normal swimming pattern, exhibiting irregular, uncoordinated movements, and may fail to stay in the middle of the water column.

2. Upside Down Swimming

One of the more visually obvious symptoms is when Neon Tetras start swimming upside down or on their sides.

This unusual behavior is a direct result of losing control of their buoyancy.

Fish cannot control their position and direction in the water, leading to these unusual swimming behaviors.

Also Read: Why Is My Neon Tetra Swimming Upside Down?

3. Abdominal Swelling

Abdominal swelling, or bloat, in neon tetras, is usually visible to the naked eye.

The swelling can occur from gas or fluid accumulation, or parasites within the swim bladder. 

The swollen abdomen can put pressure on other internal organs, adding to the fish’s discomfort.

Also Read: Why Is My Neon Tetra Fat And Bloated?

4. Inability To Stay Still

An imbalance in their swim bladder can make it difficult for neon tetras to remain still in the water.

They may continuously sink or float upward, unable to maintain a stationary position. This exhausting experience can lead to additional stress and weakness.

5. Loss of Appetite

The discomfort and stress caused by swim bladder disease often lead to a loss of appetite. The fish may stop eating altogether or eat less than usual.

This reduced food intake can exacerbate the problem by leading to weight loss and weakening the fish’s immune system, making them more susceptible to infections.

6. Lethargy

Neon Tetras with swim bladder disease often exhibit reduced energy levels. They may appear less active and more lethargic than usual.

This fatigue could be due to the effort required to deal with buoyancy problems or it can be a symptom of the overall declining health of the fish.

7. Hiding

In response to the stress and discomfort caused by the disease, neon tetras may hide more frequently.

They seek comfort and stability in decorations, plants, or the corners of the tank. This behavioral change indicates that the fish is unwell.

8. Swimming Up And Down (Vertically)

If a fish is constantly swimming up and down, this may be its attempt to regain control of its buoyancy.

Continuous, almost frantic movement can lead to exhaustion and indicates a struggle with the function of the swim bladder.

Also Read: Neon Tetra Swimming Vertically

9. Floating At The Top

In severe cases, fish may float motionless at the top of the tank, unable to control their position at all.

This is a critical symptom indicating advanced swim bladder disease. If this symptom is observed, immediate action is necessary to try and alleviate the fish’s condition.

Also Read: Why Is My Neon Tetra Floating At The Top?

How Do You Treat Neon Tetra Swim Bladder Disorder?

The treatment approach for swim bladder disorder depends on its underlying cause. Different causes necessitate distinct treatment strategies.

Here are the various treatments:

1. Treating Swim Bladder Disorder Caused by Overfeeding/Constipation

If overfeeding or constipation is the cause, follow these steps for treatment:

  • Fast your fish for 24-48 hours. Overfeeding can cause constipation, which in turn, can press against the swim bladder and cause buoyancy issues. Fasting can help relieve constipation.
  • After the fasting period, feed your fish a diet high in fiber, like cooked, shelled peas. These can act as a natural laxative.
  • Avoid overfeeding in the future. Small, regular feedings are better than large feedings.

2. Treating Swim Bladder Disease With Epsom Salt

If the previous method was unsuccessful, you can attempt to treat swim bladder disease in neon tetras with Epsom salt (link to Amazon):

  • Dissolve 1 tablespoon of Epsom salt in a separate container of dechlorinated water.
  • Add this solution to the fish tank. Epsom salt helps to reduce swelling and inflammation and can help in case of constipation.
  • Monitor your fish closely. The Epsom salt bath should help them expel any built-up waste in their system.
  • Remember, Epsom salt should be used sparingly and for short-term treatments.

3. Treating Swim Bladder Disorder Caused By Shock

If your neon tetra is experiencing swim bladder disorder due to shock, follow these steps:

  • If you notice that the temperature fluctuates consistently, try stabilizing it with a heater, aiming for 70-81°F or 21-27°C.
  • Ensure that the pH is between 6.0 and 7.0 and that both nitrite and ammonia levels are at 0 ppm.
  • If any parameter falls out of range, perform regular water changes. Remove any aggressive tank mates that bully your neon tetras.

4. How to Treat Swim Bladder Disease in Neon Tetras Caused by Bacterial/Parasitical Infection

If your neon tetra is suffering from a bacterial infection or parasite, a quarantine tank is necessary for treatment:

  • If a bacterial or parasitic infection is suspected, isolate the sick fish to prevent disease spread.
  • Consult a vet or pet expert for suitable antibiotics or antiparasitics. For bacterial infections, consider using API Melafix (link to Amazon).
  • Closely follow medication instructions, monitor fish health and complete treatment.
  • Maintaining good water quality with regular changes, proper filtration, and not overfeeding helps prevent future infections.

How to Prevent Swim Bladder Disease In Neon Tetras

Thankfully, there are several measures you can take to reduce the likelihood of your neon tetras developing swim bladder disease.

Here are the best preventive strategies:

1. Provide High-Quality Food

Choose a specially formulated, nutrient-rich food for neon tetras or small freshwater fish.

These foods have adequate nutrients and are easily digestible, reducing potential gastrointestinal problems.

I highly recommend TetraMin Tropical Flakes (link to Amazon) as they are extremely nutritious and beneficial for the health of neon tetras.

2. Ensure A Balanced Diet

While commercial food is the main diet, introduce variety with live or frozen food such as daphnia, brine shrimp or bloodworms.

A varied diet not only keeps the fish healthy but also reduces digestive problems that contribute to swim bladder diseases.

3. Avoid Overfeeding

Overfeeding can cause bloating and flotation problems. Feed small portions two to three times a day, giving only what they can consume in a few minutes.

Immediately remove residue to prevent water contamination.

4. Maintain Good Water Quality

Monitor and regularly maintain optimal water conditions, including nitrate, nitrite, ammonia, pH and hardness levels. Do weekly partial water changes and use a quality aquarium filter.

5. Keep The Water Temperature Stable

Neon tetras prefer a stable temperature between 70-81°F (21-27°C).

Rapid changes can stress your fish and lead to disease. Use an aquarium heater and consider a thermostat for precise control.

6. Remove Aggressive Tank Mates And Hazardous Decorations

Aggressive tankmates and dangerous decorations can cause stress and physical harm. 

Make sure all residents are calm and obey neon signs and avoid decorations that could cause injury.


Swim bladder disorder has various causes and symptoms, and timely identification is crucial for the health of your neon tetra.

If you’re uncertain about your fish’s condition or the appropriate treatment, I highly recommend consulting an aquatic vet.

An expert will be able to prescribe the right treatment for your fish.