Why Is My Neon Tetra Not Swimming? Shocking Causes And Solutions

neon tetra not swimming

As a devoted neon tetra owner, you know how important it is to keep your underwater friends swimming happily. However, there may be times when you notice that they’re not as lively as usual, which can cause concern.

Don’t fret; several factors can cause this behavior, such as poor water parameters, low water quality, stress and diseases, nutrition deficiency, or even external and genetic factors. Luckily, timely detection and correction can create a better environment for your neon tetras, ensuring their health and happiness.

Keep reading further if you want to know about these things in detail.

Why Is My Neon Tetra Not Swimming?

Neon tetras tend to be still when they are not in proper health or find breathing difficult. Therefore, let us study why your neon tetra is not swimming, as it can be due to the following reasons.

Wrong Water Parameters

Neon tetras are a hardy species known for their resilience and adaptability. However, as they have been in captivity for an extended period, they’ve become accustomed to the aquarium lifestyle. While this has benefits, unfortunately, it has also led to a decrease in their life cycle, making it essential to maintain the perfect water parameters for survival.

As a dedicated aquarist, ensuring that their environment is as close to their natural habitat as possible, with the right water pH level, temperature, and cleanliness is crucial.

By doing so, you’ll help them thrive in their new home, and they’ll continue to enchant you with their vivid colors and lively behavior. So, provide the best possible environment for your neon tetras, and watch them flourish in your aquarium for years to come!

Tank Water Cycle

If you are not cycling your tank properly or changing its water frequently every week, then you might see this activity in your neon tetra.

Since such activity can cause the ammonia level to rise, neon tetra may find it difficult to breathe. As a result, the oxygen level depletes, and neon tetra shows no activeness in swimming.


Diseases can cause the neon tetra to be still and not swim in the tank as freely as it does. Out of some, swim bladder disease is the most common type that can cause such problems.

If swimbladder disease is the case, it can be due to bacterial and parasitic infections in the fish. Neon tetra may even catch cancer and tuberculosis, which causes such stiffness.


Stress can be a significant factor in causing neon tetras to become inactive. These delicate creatures can easily become overwhelmed when they sense danger or even minor environmental fluctuations, significantly increasing their stress levels.

When this happens, they tend to become less active, and their usual behaviors become disrupted. As an attentive aquarium owner, monitoring your neon tetras for signs of stress and taking the necessary steps to alleviate it is essential.

By ensuring stable water conditions, reducing noise levels, and maintaining a comfortable environment, you can help your tetras feel safe and secure, allowing them to thrive and exhibit their lively and vibrant behavior once again. With your loving care and attention, your neon tetras will remain happy, healthy, and active for years to come! Find out the reasons your neon tetras can be stressed in the tank!

Poor Diet

A healthy diet is essential to keep your neon tetras in prime condition. A poor diet can cause several health issues, including bloating of the bladder, which can be quite uncomfortable for your fish. Additionally, a diet lacking in necessary nutrients can make your fish more vulnerable to disease and infection.

As a responsible aquarium owner, it’s crucial to ensure that your neon tetras are getting the right amount and variety of food to meet their nutritional requirements.

You can offer them a combination of live, frozen, and dried foods to provide a balanced diet. By providing a healthy and diverse diet, you can help your neon tetras stay strong and healthy, resist disease, and show off their vibrant colors and playful behavior for years to come.

External Factors

Some external factors can also cause stress to outbursts in fish. The neon tetra is no different.

Any physical trauma, like bad tank mates’ presence in the tank or a rapid temperature change, can cause the neon tetra to be still.

Genetic Factors

If you are doing everything right and still are unable to keep your neon tetra active, your neon tetra might be genetically defective. This means that your poor neon tetra was born with a deformed swim bladder.

Moreover, this condition is even aggravated as these fish grow older. The problem here is breeding the neon tetra so they can carry a certain trait. With the increase in popularity, people want a particular shape, size, or color of neon tetra.

Thus, causing the neon tetra to grow in a desirable format can cause genetic deformity in neon tetra. Hence, keeping them afloat and inactive.

What Do I Do To Make My Neon Tetra Active and Healthy?

You can take care of the causes I mentioned above to make the neon tetra healthy and happy. Some of the ways are mentioned below:

Maintain Water Parameters

As per the best guidance, the neon tetra must live in the following water parameters:

The Temperature of the tank water 70°F and 80°F (21°C to 27°C)
The ph of the tank water 6 and 7
The hardness of the tank water 2 dGH to 10dGH

Maintain Aquarium Cycle

The aquarium cycle means its nitrogen cycle. The ammonia and nitrite levels in the aquarium must be absolute zero. Similarly, the nitrate levels must be less than 10 ppm.

You must change your water every other week from 20 percent to 25 percent to maintain a good nitrogen cycle.

Quarantine The Diseased Fish

Your neon tetra might not be swimming if they live with diseased fish. If you find a diseased neon tetra, take it and isolate it into another tank as fast as possible.

Then, give it extra care and feed it properly until it feels better.

Good Diet And Nutritious Food

A nutritious diet is pretty important for any living being on earth. The same goes for your beloved neon tetra. You must feed it properly for its color to stay as bright as it is. This means you require the best diet with proper balance and nutrition.

You can even bring the neon tetra back from the diseases it has been suffering from just by feeding it properly. Some of the good food options are:

Image Food  Link

Josh’s Frogs Melanogaster Fruit Fly Culture Kit (Makes 10 Cultures) buy amazon
Ocean Nutrition Instant Baby Brine Shrimp 0.7-Ounces (20 Grams) JarBrine shrimp buy amazon
1000+ Live Daphnia Magna buy amazon
Exotic Nutrition Bulk Dried Black Soldier Fly Larvae (10 lbs.) – High-Calcium Insect Treat buy amazon
9 OZ Matured Micro worm Mega Culture – Ready to Harvest – Live Fish Food buy amazon
SAN FRANCISCO BAY Brand Freeze Dried Bloodworms 1.75oz buy amazon
San Francisco Bay Brand/Sally’s Freeze-Dried Bacteria Free Tubifex – 4 oz. buy amazon
Ancestral Supplements Grass Fed Beef Heart (Desiccated) — Natural CoQ10 (180 Capsules) buy amazon
Uncle Jim’s Worm Farm 500 Count Red Wiggler Live Composting Worms buy amazon
Hikari Tropical Micro Pellets (1.58 (2 Pack)) buy amazon
Tetra PRO PlecoWafers 2.12 Ounces, Nutritionally Balanced Vegetarian Fish Food buy amazon
Tetra TetraFin Goldfish Flakes 4.52 Pound Bucket, Balanced Diet buy amazon

Correct Tank Size

The neon tetra needs perfect space for it to roam around.

You can add 5 to 6 neon tetras in a 10-gallon tank for this.

You may add an extra gallon for every extra neon tetra you add up.

Schooling Neon Tetras

You shall keep neon tetras in schools of 5 to 6 so they do not stress.

These are schooling fish and can be intimidated by other fish species. You may see that schooling these in groups will make them more comfortable and more active in the tank.

External Factors

The temperature increase or decrease is a major factor for it to be inactive. So, make sure you keep the temperature stable by keeping a heater and a thermometer to check the water temperature.

Moreover, you can add air pumps for more oxygenation, filters for better water quality, and lighting for the correct bio-topic aquarium feeling.


You can use plants and decors for the neon tetras to hide and be safe in.

In such a way, they can feel comfortable in the small tank they live in and create a better healthy state of mind. Likewise, adding some dried leaves as in their natural habitat will make them feel at home.

Frequently Asked Questions

Why Does My Neon Tetra Swim in Circles?

Neon tetras swim abnormally when they are sick. These fish will swim in circles when they do not feel well, making them twitch in the tank water. You might even view the neon tetra as being more inactive and does not respond to food in such a case.

How Can I Tell If My Neon Tetras Are Sick?

The sick neon tetras show the following signs:

  • Swimming irregularly in the tank
  • Bumping into other fishes
  • Being inactive
  • Swimming to the top for the search for oxygen
  • Swimming upside down
  • Being aggressive
  • Bloated body
  • Not responding to food or not eating at all

Can A Neon Tetra Fish Fight With Other Fish?

Neon tetras are quite the active fish in the fish kingdom. That is why it is hard to differentiate whether they are fighting or playing with their tank mates. But, honestly, the neon tetras love chasing other fish in the tank.

However, it is not a major concern for the people as they mean no harm. Yes, neon tetras can fight, too, but only if you do not give them the appropriate space it needs. Even when they are mating, the behavior can get a little aggressive. At other times, they are not that aggressive.

Last Words

Thus, you can now understand why your neon tetra might not be swimming.

With small adjustments to their diet and water parameters, you’ll have a lively and vibrant aquarium filled with beautiful neon tetras. So, take good care of these delightful creatures and enjoy the serene and mesmerizing beauty they bring to your home. Happy fish keeping!

If you find it out on time, you can still create a better environment for your neon tetra. Thus, making them healthier and happier. In addition, neon tetras are not very difficult to fish to look after.

Related article:

  1. How Many Neon Tetras Should You Keep In School?
  2. How To Breed Neon Tetras – A Complete Step By Step Guide
  3. Does water pH level affect neon tetras?
  4. How Long Can Neon Tetras Live Without Food
  5. How To Prepare Best Homemade Neon Tetra Food – DIY Fish Food

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top