Are Cardinal Tetras Prone To Bloating?

As people today are showing more interest in keeping fish as pets, there are a lot of questions and concerns that come up. It’s a question that has been on the minds of many fish owners, Are Cardinal Tetras Prone To Bloating?

Indeed it is. The answer to this question can be present in the water parameters for these fish. They are not prone to bloating if the pH level is below 7, nitrite levels are less than 10ppm, and ammonia levels are less than one ppm. It also helps if you feed Cardinal tetras live food rather than frozen food.

The cause of bloating can be due to a variety of factors. But there are many ways to prevent and treat it. In this post, we will talk about what causes bloat in fish, how to treat it and prevent it.

Do Cardinal Tetras Bloat?

Even though Cardinal tetras are easy to keep, they are susceptible to their environment and water conditions. One of the most common issues with these fish is bloating. Fish bloat can be particularly tricky to treat.

Bloating is a symptom of many issues, including constipation and bacterial infection. In some cases, bloating may be an indicator that your tank needs more aeration or filtration.

When cardinal tetra fish bloat, it is often because of excess air in their digestive tract. It usually results due to overfeeding or the use of poor quality food that is difficult to digest.

Moreover, cardinal tetras are omnivores that can eat anything. Usually, they eat easily and may swallow air while eating. So, bloating is quite common in cardinal tetra.

Are Cardinal Tetras Prone To Bloating?

Yes, cardinal tetras are prone to bloating. However, fish are very particular and sensitive to their environment and aquarium conditions.

Some cardinal tetras are at higher risk for bloating than others

  • Young or pregnant females (in particular),
  • Fish with constipation, intestinal worms, or excess food in their digestive system.
  • Fish with a poor diet
  • Mature specimens living in tanks smaller than 20 gallons.

An important thing to remember is that just because you have one bloated fish, it doesn’t mean the rest has the same infection. But if your whole population starts bloating, this may indicate an issue specific to your tank rather than the fish.

What Are The Causes Of Bloating In Cardinal Tetras?

Cardinal tetras are small, peaceful fish that often lives in schools. They are a popular choice for beginner aquarists and experienced hobbyists alike because they adapt well to different tank conditions and have an attractive coloration.

However, cardinal tetras can be sensitive to water parameters if not properly cared for. So, it’s important to understand what factors causes bloating:


If a cardinal tetra is egg-bound, it will begin to bloat. Egg binding occurs when eggs block an oviduct or fish that due to improper laying. The result of this blockage causes the fish’s body to swell from fluid retention and can be fatal if left untreated.

Inadequate Water Conditions

One of the most common causes for bloating in cardinal tetras is due to inadequate water conditions. When exposed to polluted or dirty water containing high nitrogen and carbon dioxide levels, these fish often feel bloated.  It can cause fluid retention and eventual death if you fail to address it promptly to a veterinarian.


Cardinal tetras with dropsy are also prone to bloating. Dropsy is a disease that results due to the internal organs of the fish swelling with fluid retention, which causes its scales and skin to protrude outwardly.

Internal Bacterial Infection

A bacterial infection can cause bloating. If you think your fish is bloating, they may have internal bacteria ills. So, it will need proper treatment with antibiotics before the problem exacerbates further.

External Parasites

Cardinal tetras are prone to external parasites if not cared for properly or their environment isn’t clean enough. A parasite infestation causes swelling and bloating, and you can identify it by visible worms or white spots. For example, Hexamita or HITH is a parasite that causes bloating and other symptoms in cardinal tetras.

Tissue Damage

If your fish have wounds, they may swell up as a result of damage to their tissue. It is hazardous for cardinal tetras because it often results in internal infections that cause more serious problems over time.

Poor Diet

Fish who are fed an improper diet will bloat and become more susceptible to bacterial infections. If you’re feeding them the wrong foods, consider switching over to a high-quality pellet food that contains all of the necessary nutrients your fish needs for healthy growth.

Usually, fish who are overfed will bloat and become more susceptible to bacterial infections. Similarly, sometimes Cardinal tetras may be bloating and have a distended abdomen may also be suffering from constipation.


Cardinal tetras can live best in schools. But, it would be best if you never overcrowded them together with other fish. If you have too many cardinal tetras in a tank, they may feel stressed and begin fighting with one another or compete for food.

Inadequate Tank Size

Another common cause of bloating has an aquarium that’s not big enough to accommodate your school of cardinal tetras comfortably. Again, be sure to research each species you plan to keep and select a tank size that meets your needs.

If you think your cardinal tetra may be suffering from any one of these conditions or if it begins showing signs of bloat, it’s important to seek veterinary care immediately.

What Are The Symptoms Of Bloating In Cardinal Tetras?

Most owners take bloating casually, but it is actually a serious problem that requires immediate attention. If you fail to manage this condition, the fish will die a painful death.

Symptoms of bloating can include

  • An enlarged stomach that is visibly protruding from the body’s midsection,
  • Swollen scales on the abdomen and lower fins as well as around the eyes,
  • A discolored belly (white or grey) with red or pink fins,
  • Difficulty swimming and staying upright due to the weight of its bloated body.

If your cardinal tetra shows any of these symptoms, you should immediately take it to a veterinarian (preferably one that specializes in aquatic animals). A veterinarian can treat your fish by flushing the bloating toxins from its body and ensuring that you keep an ideal environment for this freshwater fish species.

How To Treat Bloating In Cardinal Tetras?

Cardinal tetras are popular aquarium fish, but they aren’t always the hardiest. They do best in tanks with plants and live sand substrate to reduce stress on them. If you notice bloating in your cardinal tetra, try these steps:

  • Use erythromycin and doxycycline for bacterial infection
  • Use metronidazole for parasitic infections
  • Increase the temperature of your tank to 86 degrees F and use Epsom salt at a dose of one teaspoon per five gallons. This can help with bloating from constipation or swim bladder disorder and other internal parasites that cause gas buildup in the fish.
  • Make sure you have enough hiding spots for your fish.
  • Make sure you are not overfeeding them.
  • Increase the water changes to once a week instead of every two weeks.
  • Remove any sharp objects from the tank, including plants that can damage their skin and fins when they get too close.

If one of your cardinal tetras seems to bloat, it’s best to quarantine them to prevent the infection from spreading.

How To Prevent Bloating In Cardinal Tetras?

Prevention is always better than cure. So, if you want to make your Cardinal tetras safe from health issues like bloating, you can adopt certain measures.

Watch Water Conditions:

Make sure you keep a check on the water conditions of your aquarium where Cardinal tetras are present. You might have to change 20% or more water every week depending upon the number of fish and size of the tank. In case if required, take help from professionals who know how to maintain different types of fish tanks.

Watch Feeding Habits:

Overfeeding your Cardinal tetras is the first step towards health issues like bloating, discoloration of the skin, and death of the water environment. So, make sure you feed them on time with the required food only. Check the feeding chart to know more about how much they eat in a day.

Proper Temperature:

The temperature of the water plays an important role in fish’s health. So, make sure you maintain the right amount of temperature inside the Cardinal tetras’ tank. It should be somewhere between 70°F to 79° F (20-26’C). Higher or lower than this range may cause serious health issues.

Gravel Cleaning:

Cardinal tetras are prone to bloating when there is an accumulation of poisonous gas in the tank due to dirty gravels at the bottom end of their aquarium. So, make sure you clean them regularly and keep a check on water conditions every week.

Reduce Stress:

Most of the time, fish get bloating and other diseases due to stress. So, always keep a check on their surroundings whether they are comfortable enough or not. Try providing them with required things like shelter, hiding places, etc., so that they can feel safe in this environment which is new for them after all!

Regular Medical Checkup:

Always keep a check on their health conditions by regular medical examinations, which include checking the water quality, temperature, etc., with the help of professionals who know how to maintain the saltwater tank.


Overall, Cardinal Tetras are hardy and easy to care for fish. Like all fish, they do have some risk of bloating, but this is not a common issue with the Cardinal Tetra when cared for properly. If you want more information on taking proper care of your Cardinal Tetras, don’t hesitate to get in touch with us.

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