Neon Tetra Disease: 6 Main Causes Of Your Pet’s Distress

Last Updated: March 1, 2023 by Dave Gibbins

Neon tetras are hardy fish that can tolerate different water conditions. These beautiful fish are popular among beginners and aquarium hobbyists. But, they are not hardy to neon tetra disease. Neon tetra disease has proven a menace because it can wipe the entire population in your aquarium.

But, what causes neon tetra disease? 

What are the symptoms of neon tetra disease? How can one prevent or treat neon tetra disease? This article provides answers to these questions. Read on.

Neon Tetra Disease

Neon tetra disease is a condition that affects not only neon tetras but other fish species. It was first diagnosed in neon tetras, but barbs, danios, angelfish, zebrafish, guppies, Rasboras, and other tetras can get infected. The cardinal tetras, however, are more resistant to the disease.

The parasite belongs to spore-forming parasitic fungi that produce infectious and resistant spores. These spores enter the fish’s body once they consume bodies of infected fish or infected live food like tubifex.

The sporoplasms affect the fish’s tissues and organs, including the stomach, digestive tract, intestines, and skeletal muscles. As the disease progresses, it causes the muscles and organs to degenerate, slowly killing the fish.

Is neon tetra disease contagious? Yes, in the sense that healthy fish will get infected from consuming the remains of other dead fish.

Causes Of Neon Tetra Disease

This disease is caused by Pleistophora hyphessobryconis. This parasite consumes your fish inside out.

The parasite enters the host fish body when:

• The fish eat other dead, infected fish.
• The fish eat live food servings that are infected.
• Your fish have compromised immunity, and the parasite is thriving in the tank.
• You introduce affected fish into the aquarium.

The parasite enters the digestive tract and then spreads to the tissues, muscles, organs, and skeleton.

Pleistophora hyphessobryconis can thrive in fish tanks with warm water, low pH, reduced oxygen levels, and organically rich conditions. Most fish get stressed living in such conditions, which makes them susceptible to developing infections and neon tetra disease.

If you suspect your fish have neon tetra disease, here are the signs to watch out for.

Symptoms of Neon Tetra Disease

Diagnosing neon tetra disease can be challenging since it exhibits the same symptoms as other bacterial and parasitic infections. Nevertheless, fish with this condition exhibit the following symptoms:

1. Restlessness

Infected fish will become restless and change their swimming patterns in the initial stages. This is easier to spot among schooling fish or active fish. You will also observe your fish swimming in erratic patterns.

2. Hiding

Your sick fish will retreat and hide in live plants or caves. They will limit their interaction with other fish as they try to regain the energy drained by the disease. Additionally, the infected fish will have difficulty swimming around the fish tank.

3. Dull Colors

Sick neon tetras will also start to lose coloration. They will look pale, a sign that the neon disease has attacked the muscle tissue. However, losing coloration may not necessarily mean your fish have neon tetra disease. Fish usually turn pale when stressed.

4. White Cysts

Sick neon tetras develop white cysts and bumps as the disease progresses. After the parasite attacks the intestinal wall, it advances to the muscle tissues, which causes the development of cysts. The cysts may also become lumpy.

5. Curved Fish’s Spine

With time, the sick fish’s muscles and tissues waste away. At this stage, the straight, blue color line on your neon tetras will distort into an “S” shape. The fish’s tail will also have a downward turn.

6. Secondary Infections

Moreover, your fish will develop other infections such as bloating and fin rot. Neon tetra disease weakens a fish’s immune system, opening doors for other infections.

False Neon Tetra Disease

Did you know there is false neon tetra disease? Its actual name is columnaris, a condition that has very similar symptoms to neon diseases.

The key signs of columnaris are white spots on the fish’s body.

The white spots are similar to the white cysts that sick neon tetra have. Fortunately, a dose of antibiotics can treat columnaris. Moreover, the disease has milder effects than neon tetra disease.

Here is a YouTube video explaining the causes and treatment for Columnaris:

Treatment For Neon Tetra Disease

Currently, there is no effective medication for treating neon tetra disease. Once you spot the signs, remove all affected fish to avoid infecting the entire tank.

Some fish medications offer temporary relief by preventing further infections. But, they do not cure this fatal disease.

It may take weeks or months before your neon tetras succumb. Many aquarium hobbyists choose to euthanize sick fish to stop the suffering.

If euthanizing your fish does not check your boxes, you can try:

Antibacterial Treatment

It will not hurt to try this treatment since neon tetra disease mimics the signs of a bacterial infection.

Remember that antibacterial treatment will only prove effective when treating bacterial infections, not neon tetra disease. If your fish recover through this treatment, they were suffering from false neon tetra disease.

Medicated Bath

Alternatively, bathe your sick fish in methylene blue for 10 days to clear parasitic infections. The benefits of a medicated bath are:

• Treating open sores that make the fish susceptible to more tissue infections.
• Promotes faster healing by promoting osmoregulation.
• Prevents bacterial growth
• Promotes oxygen absorption in the tissues

During this treatment plan, avoid overdosing the methylene blue as it can destroy the beneficial bacteria in the tank.

How to Prevent Neon Tetra Disease

With neon tetra disease, prevention is more practical than treatment. Here is what you can do to prevent neon tetra disease:

1. Do Not Purchase Sick Fish

Before you purchase fish, inspect their condition at the pet store. Do not bring neons home if they do not look healthy. Some signs of sick neon tetra fish are pale coloration and not schooling with other tetras.

2. Quarantine Fish

If the fish look vibrant and colorful, bring them home but do not introduce them to the community tank yet. Keep the new fish in a separate quarantine tank for up to two weeks to monitor whether they harbor any parasites and diseases.

Additionally, quarantine new plants before adding them to the main fish tank.

3. Buy Live Foods From Reputable Stores

Live food like tubifex is at times responsible for the transmission of the parasitic organism causing neon tetra disease. Therefore, always purchase live foods from trustworthy pet stores.

Alternatively, you can feed your neon tetras fish flakes as they are less likely to pass infection.

4. Remove Infected Fish

Neon tetra disease is highly contagious. Remove all sick neon tetra from the tank to prevent further infections and place them in a hospital tank.

5. Maintain a Healthy Environment

Poor water parameters can promote the growth of deadly pathogens. Besides, these freshwater fish are prone to developing infections if the tank water is not clean.

To maintain a healthy tank, you should:

Clean The Fish Tank Weekly

We recommend cleaning your fish tank at least once every week. Remove fish waste, uneaten food, dead fish, and dead plant matter, siphon the substrate, and wipe the tank walls with filter floss.

This maintenance routine may require that you spend 30 minutes to 2 hours. But, it will go a long way in preserving your fish’s health.

Perform Water Changes

You should also perform weekly water changes. We recommend changing 10 to 20% of the aquarium water. The new water should have a similar temperature and hardness as the old tank water to prevent temperature shock.

Also, do not add tap water directly into the tank as it contains chlorine and chloramine. These chemicals are harmless to humans. However, they will destroy your colonies of beneficial bacteria in the tank.

Moreover, chlorine and chloramine can burn your neon tetra’s lungs.

Test The Water Regularly

Testing the tank water will help you monitor the water parameters in the aquarium. Test the water for ammonia, nitrites, and nitrate levels. The ammonia and nitrite levels should be 0 ppm. Since neons are freshwater fish, the nitrate levels should be 10 ppm.

Furthermore, check that the pH range is between 6.5 to 7.5 and that the carbonate hardness level is 1 to 2 dKH.

Change Filter Media

Filters remove waste, debris, and ammonia buildup from the water to maintain a clean, healthy tank. However, they too need cleaning.

Filter inserts and media can harbor dangerous bacteria. This is why you should rinse the filters every two weeks and change the inserts when necessary. When cleaning, use treated water to avoid killing the healthy, nitrifying bacteria.

Add UV Sterilizers

UV sterilizers can help you prevent algae growth, bacteria buildup, and other microorganisms in freshwater tanks and marine aquariums.

Although aquarium filters clean the tank water, they are not built to kill microorganisms. UV sterilizers expose these parasites and organisms to radiation, thereby preventing their growth.

In addition, these sterilizers improve redox balance to strengthen the neon tetra’s immune system.

6. Clean The Community Tank

If some of your neons have the neon disease, you must clean the main tank to clear the parasites and infection. Here is a step-by-step guide on how to clean the tank.

Step 1: Mix 1:8 ratios of bleach and water. The bleach should constitute one part with eight parts water.

Step 2: Spray this bleach solution on your tank and tank equipment.

Step 3: Let it sit for 20 minutes.

Step 4: Rinse the aquarium.

Step 6: Let the tank air dry for a day.

Step 7: Add de-chlorinated water into the tank and let it sit for two hours.

Step 8: Empty the water, then refill the tank with more de-chlorinated water.

Step 9: Complete the nitrogen cycle.

Step 10: Introduce new fish once the tank is fully cycled.

Remember to quarantine the new fish before introducing them into the established tank.

Frequently Asked Questions

How Long Do Infected Fish Die from Neon Tetra Disease?

It may take weeks or months before your sick neon tetra succumb. Tank conditions, stress, and overall health greatly influence how long neon tetra fish live after the infection.

Do All Neon Tetras Carry This Condition?

No. The condition was first discovered in neon tetra species but affects other ornamental fish. Cardinal tetras are more resistant to neon tetra disease. However, they also get affected at times.

Is Neon Tetra Disease the Same as Cardinal Tetra Disease?

Yes. These neon tetra diseases are similar and have the same symptoms. Cardinal tetras are resistant to the disease but not immune.

Is Neon Tetra Disease Contagious?

Yes, neon tetra disease can be communicated when an infected fish schools with healthy fish or when the aquarium fish consume the remains of infected fish. The infection may take a few hours or days to pass.

Does Neon Tetra Disease Affect Humans?

No. Neon tetra disease is fatal to neon tetras and other fish species but does not affect humans.

Final Thoughts

Neon tetra disease is a degenerative condition for neon tetras and their tank mates. It affects the fish’s tissues, muscles, and organs, leading to death. The disease is caused by consuming infected dead fish or infected live food.

The good news is this disease is preventable. So, always quarantine new fish and plants, buy high-quality live food from reputable pet stores, and maintain a healthy environment so your neon tetras can live a long and happy life.