Why Do Neon Tetras Twitch? (With 5 Quick Solutions)

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Seeing calm fish like neon tetras suddenly twitch and shake their entire body can be pretty worrying. That was at least how I felt when I first noticed this in my aquarium.

Over the years, I learned that there are many causes behind twitching in neon tetras, each with its own ways to overcome it.

In this article, I will walk you through the causes of shaking in neon tetras, and take you step-by-step on how to fix it quickly.

Let’s get right into it.

What Does Twitching In Neon Tetras Look Like?

Twitching in neon tetras usually presents as irregular, rapid, and jerky movements that seem out of character for these normally smooth-swimming fish.

They may dart around the tank erratically, shake their bodies, or have spasmodic body twitches, which are noticeable because they’re unlike the regular swimming patterns of neon tetras.

What Causes Twitching In Neon Tetras?

1. Water Chemistry Changes

Water chemistry has a huge impact on the health and behavior of aquarium creatures, including the neon tetra.

Twitching may be an early sign of water chemistry imbalance. Let’s explore this further:

  • Imbalance in pH: Neon tetras prefer slightly acidic water conditions, with pH ranging between 5.0 to 7.5. Sudden or consistent changes in pH outside this range can induce stress, causing twitching.
  • Hardness variations: The hardness of the water, defined by its mineral content, can affect neon tetras. They thrive in soft water, and too much hardness might lead to twitching behavior.
  • Temperature fluctuations: Neon tetras are tropical fish and prefer water temperatures between 70-81°F (21-27°C). Swift changes or inappropriate water temperatures may provoke twitching.
  • High ammonia levels: The presence of ammonia, often caused by fish waste, uneaten food, and decaying plant material, can be toxic to neon tetras and lead to twitching.
  • Poor oxygenation: Just like us, neon tetras need oxygen to survive. Inadequate oxygenation can induce stress and result in twitching.
  • High nitrate concentration: Nitrates are less harmful than ammonia, but high levels over time can negatively impact neon tetras, causing them to twitch.

2. Stress

Stress is a significant factor contributing to abnormal behavior, such as twitching in neon tetras. Let’s unpack some causes:

  • Overcrowding: If an aquarium is too crowded, the neon tetras might feel stressed. They need enough space to swim around freely.
  • Inadequate hiding spots: Neon tetras need plants or other structures to hide. A lack of these can cause them stress, leading to twitching.
  • Loud noises: Constant exposure to loud noise can induce stress in neon tetras, manifesting as twitching.
  • Incorrect light conditions: Neon tetras require a balance of light and dark. Excessive light or sudden changes can cause stress, resulting in twitching.
  • Rapid environmental changes: Swift alterations in their environment, such as moving the tank or introducing new fish, can stress neon tetras, leading to twitching.

Also Read: Stress In Neon Tetras

3. Disease

Diseases can affect the well-being of neon tetras, causing twitching among other symptoms. Here are some diseases and their causes:

  • Neon Tetra Disease: This is a common, highly infectious disease that can cause twitching in neon tetras before other symptoms like color fading or cysts appear.
  • Parasitic infections: Parasites like ich or velvet can cause twitching in neon tetras as they try to dislodge the irritants.
  • Bacterial infections: Certain bacterial infections can affect the nervous system of neon tetras, leading to twitching.
  • Viral infections: Some viral infections can also induce twitching in neon tetras, though these are rarer in aquarium conditions.
  • Fungal diseases: Fungal diseases often come with physical symptoms, but in some cases, they may cause neon tetras to twitch.

4. Spawning Behavior

During spawning, neon tetras can display different behaviors, including twitching. Let’s understand why:

  • Mating rituals: Male neon tetras may twitch as a part of their courtship display to attract females.
  • Pre-spawning agitation: Females can twitch before releasing eggs as a response to hormones and the internal pressure of carrying eggs.
  • Post-spawning stress: The physical exertion of spawning may result in twitching in both males and females.
  • Protection of eggs: Both sexes may twitch as an alarm or deterrent to other fish approaching their eggs.
  • Spawning-induced stress: Changes in behavior during the spawning period can induce stress, causing neon tetras to twitch.

Also Read: Why Is My Neon Tetra Not Moving?

5. Aggression

While neon tetras are generally peaceful, aggression can lead to twitching. Here’s how:

  • Territorial disputes: Neon tetras can become aggressive if they feel their territory is threatened, leading to twitching behavior.
  • Bullying: In a tank, if some neon tetras are bullied or harassed by other fish, they may twitch due to stress or fear.
  • Competing for food: Neon tetras may twitch while competing for food, especially if food sources are limited.
  • Imbalanced male-to-female ratio: If there are too many males and too few females, the males may become aggressive, leading to twitching in the community.
  • Mixing with aggressive species: Neon tetras kept with more aggressive species might twitch due to fear or stress.

Also Read: Why Is My Neon Tetra Turning Black?

How To Reduce Twitching In Neon Tetras

If your neon tetra continuously twitching and shaking its tail, follow these steps:

1. Addressing Water Chemistry Changes

Addressing water chemistry changes is crucial in reducing shaking behavior in neon tetras. Here’s how you can manage these changes:

  • Consistent water testing: Regularly test pH (should be between 6.0 to 7.0), ammonia, nitrate, and other parameters to maintain a healthy environment for your neon tetras. I do that with the API FRESHWATER MASTER TEST (link to Amazon).
  • Maintain optimal temperature: Ensure a stable water temperature within the range of 70-81°F (21-27°C) using a reliable aquarium heater. My recommendation: Orlushy Submersible Aquarium Heater (link to Amazon).
  • Scheduled water changes: Conduct weekly water changes, replacing about 25-30% of the tank water, to remove harmful toxins.
  • Proper tank aeration: Use an aquarium air pump or a filter with good surface agitation to ensure adequate oxygenation for the neon tetras. I personally recommend the Hygger Aquarium Air Stone (link to Amazon).
  • Control water hardness: Use water conditioners or mix RO/DI water to keep the water hardness at suitable levels for neon tetras.

Also Read: Do Neon Tetras Need A Heater?

2. Managing Stress

Reducing stress is paramount for the well-being of neon tetras and can help decrease irregular shaking behavior. Here’s how:

  • Provide adequate space: Avoid overcrowding in your aquarium to give each neon tetra enough space to swim and explore.
  • Ensure suitable lighting: Maintain a balanced lighting schedule to mimic a natural day-night cycle for the neon tetras.
  • Create hiding spots: Install decorations, rocks, or live plants to provide hiding places for the neon tetras and reduce their stress levels.
  • Minimize noise: Keep the aquarium in a quiet location and avoid sudden loud noises that can stress the neon tetras.
  • Limit environmental changes: Avoid making sudden changes to the tank environment to prevent stress for your neon tetras.

I also suggest avoiding aggressive tank mates in your neon tetra’s tank, including: 

  • Green Terror (Andinoacara rivulatus)
  • Convict Cichlid (Amatitlania nigrofasciata)
  • Jaguar Cichlid (Parachromis managuensis)
  • African cichlids (various species, such as Mbuna cichlids from Lake Malawi)
  • Jack Dempsey (Rocio octofasciata)
  • Red Devil Cichlid (Amphilophus labiatus)
  • Flowerhorn Cichlid (Hybrid cichlid)
  • Oscar (Astronotus ocellatus)

Favor peaceful species instead, like:

  • Cherry Barb (Puntius titteya)
  • Celestial Pearl Danio (Danio margaritatus)
  • Pygmy Corydoras (Corydoras pygmaeus)
  • Ember Tetra (Hyphessobrycon amandae)
  • Glowlight Tetra (Hemigrammus erythrozonus)
  • Harlequin Rasbora (Trigonostigma heteromorpha)
  • Endler’s Livebearer (Poecilia wingei)
  • Cardinal Tetra (Paracheirodon axelrodi)

Also Read: 19 Great Neon Tetra Tank Mates

3. Combating Disease

Treating diseases early can help to reduce twitching and improve the overall health of your neon tetras. Here’s how:

  • Regular health checks: Monitor your neon tetras daily for any signs of disease or abnormal behavior.
  • Quarantine new fish: Always quarantine new fish before introducing them to the main tank to prevent the spread of disease.
  • Use appropriate medication: If a disease is detected, use appropriate medication under the guidance of a fish health professional.
  • Maintain good water quality: Keeping the water clean and free from harmful substances can prevent the onset of many diseases in neon tetras.
  • Feed a balanced diet: Providing a nutritious diet helps to boost the immune system of your neon tetras, reducing the risk of disease.

Also Read: 17 Neon Tetra Diseases & Their Treatments

4. Managing Spawning Behavior

Follow these steps if you suspect that your neon tetra is shaking due to spawning:

  • Provide a breeding tank: Set up a separate breeding tank to prevent stress and allow controlled spawning for your neon tetras.
  • Ensure a balanced sex ratio: Try to maintain an equal number of male and female neon tetras to avoid any spawning stress.
  • Monitor their behavior: Keep an eye on the neon tetras during spawning to detect any excessive twitching and manage it promptly.

Also Read: Neon Tetra Eggs 101

5. Tackling Aggression

As mentioned earlier, aggression is many times accompanied by shaking and twitching. Here are some strategies to overcome this:

  • Choose compatible tankmates: Ensure the tankmates for your neon tetras are peaceful and compatible to avoid aggression.
  • Provide enough food: Feed your neon tetras adequately to prevent food competition which might lead to aggressive behavior. 
  • Ensure sufficient space: Overcrowding can cause territorial disputes among neon tetras, so provide enough space in the tank.
  • Monitor fish behavior: Regularly monitor your tank to identify any signs of aggression early and intervene if necessary.

Also Read: 19 Great Neon Tetra Tank Mates


Shaking in neon tetra should not be ignored. These are relatively peaceful fish that shouldn’t present such jerky movements.

When they do, it is essential to explore further. Start by checking the water parameters to see if they fit neon tetras, with temperature, pH, and ammonia in particular.

You should also check for signs of disease. If something seems wrong, don’t hesitate to consult an expert. Aquatic veterinarians will provide you with the most accurate answer.