14 Common Black Neon Tetra Problems

Last Updated on 2024-05-14

Black neon tetras are admired for their resilience and minimal care requirements, making them a popular choice for aquarium enthusiasts. However, even these hardy fish are not immune to health issues. From parasitic infections and ich to bacterial diseases and the effects of suboptimal water conditions, black neon tetras can face several health challenges. This article delves into the most common ailments affecting black neon tetras and provides practical solutions to help you maintain a healthy aquarium environment.

Table of Contents

No 1- What To Do if My Black Neon Tetra Swimming Sideways

Seeing one of your black neon tetra swimming sideways is always alarming. Most of the time, if your fish swim strangely, it could mean something is wrong with them. Here’s a list of reasons why your black neon tetra is swimming sideways and what you can do to help them.

1. Swim Bladder Disease

When a fish is swimming sideways, the first thing that would come to mind for any experienced aquarist is swim bladder disease. It is actually not a disease but a condition where the fish lose control of their swim bladder, which helps them stay upright and float. Depending on what made your tetra sick, you can give them cooked peas, not feed them for a few days, or give them antibiotics.

2. Shock

Even though tetras are hardy fish, sudden environmental shifts can easily stress them. When there is a sudden change in the water’s temperature, pH level, amount of ammonia and nitrates, or even lighting, they can get shocked and tend to swim sideways. Shock usually kills fish, but if you catch it early, you can bring the water parameters back to what they should be for tetras and keep them stable to save them.

3. Constipation

Your fish might also be swimming sideways if they are constipated. If your black neon tetras are bloated, it could be that their enlarged stomach is pressing on their swim bladder, making them swim oddly. If so, you can help your tetras pass waste by giving them high-fiber foods like daphnia and cooked peas.

4. Parasites

Parasites are also a likely cause of why your fish may be swimming sideways. Like, the callamanus worms infect your fish and stay on their stomachs. This can cause their stomachs to swell, putting pressure on their swim bladder and making them swim in strange ways. Before using a fish dewormer on your black neon tetra, ensure you know it has parasites.

5. Bacterial Infection

Bacteria can also infect your black neon tetra, especially in their swim bladders, making them swim sideways. Some bacteria can cause the swim bladders of your fish to get inflamed, putting pressure on their swim bladder. You can do a small water change, apply a multipurpose antibiotic, and add one tablespoon of aquarium salt per gallon to get rid of the bacteria.

6. Swallowed Too Much Air

Most aquarium fish have two air sacs that work as a swim bladder, with the larger one being directly connected to the stomach. If you feed your tetras more floating food while they are eating, they may swallow too much air, which will cause their swim bladder to swell and cause them to swim sideways.  You can let your tetras go without food for a while and let them pass gas until they swim upright.

7. Poor Water Conditions

Your tetras may be swimming sideways because the nitrate levels in the water in their fish tank are high. Nitrate poisoning happens when fish are exposed to slowly rising levels of nitrate, which is commonly caused by not cleaning the tank regularly, overfeeding the fish, or having too many fish in the tank. To fix this, do a partial water change of about 15% and monitor the nitrate levels in your fish tank.

No 2- What To Do if My Black Neon Tetra Have Stripes On Their Body

The Black Neon Tetra is a unique and attractive fish species with an eye-catching black body and bright neon stripes. Many aquarists are captivated by this species and often ask why these fish have stripes on their body. Here are five reasons the Black Neon Tetra has stripes on its body.

1. Camouflage

The Black Neon Tetra stripes help them blend into their environment, making it difficult for predators to spot them. The stripes also help them hide from other fish in the tank, which reduces their stress levels.

2. Attract Mates 

The stripes on the Black Neon Tetra can act as a signal to attract potential mates. Male fish will display their stripes more prominently in an attempt to show off and attract female fish.

3. Temperature Regulation

Stripes are found in many aquatic animals, such as sharks and dolphins, which helps them regulate their body temperature. The stripes on the Black Neon Tetra have a similar function, as they can help to keep the fish warm in cold water.

4. Identification

The unique pattern of stripes on each individual Black Neon Tetra helps them to identify each other. This is important when it comes to socializing and forming relationships with others of their own species.

5. Communication 

Finally, the stripes on the Black Neon Tetra can also help them communicate with their peers and other species in the tank. The brightness of their stripes can indicate to others how they feel if they feel threatened and can also help warn other fish that they aren’t safe to eat. 

Beaituful black neon tetra

No 3- What To Do if My Black Neon Tetra’s Has Stripes On Their Body

Once you understand why the Black Neon Tetras have stripes on their body, it’s important to know how you should care for them. Here are some tips to help you give your Black Neon Tetras the best care possible. 

1. Provide Plenty of Hiding Places 

The stripes on the Black Neon Tetra can make them more vulnerable to predators. To help keep your fish safe, provide plenty of hiding places in the tank, such as caves and driftwood, for them to hide in.

2. Maintain Clean Water 

Keeping good water quality is essential for all aquarium fish, especially for Black Neon Tetras. Make sure to do regular water changes and monitor the pH levels of the tank to ensure that the water is safe for your fish. 

3. Feed a Balanced Diet 

To keep your Black Neon Tetra healthy and happy, it’s essential to feed them a balanced diet. Offer a variety of foods such as flakes, pellets, frozen, or live food.

4. Provide Tank Mates 

Black Neon Tetras are social fish and need tank mates to keep them company. Choose compatible fish of similar size that will not harass or bully your Black Neon Tetras. 

5. Monitor Stress Levels 

The stripes on the Black Neon Tetra can indicate how stressed they are. If the stripes start to fade, it may be a sign that your fish feels uneasy or threatened. Keeping an eye on their stress levels and taking action quickly can help prevent further stress. 

No 4- What To Do if My Black Neon Tetra Have a Big Belly

A black neon tetra might get swollen for many different reasons. You can treat them in different ways depending on what made them sick. Here are some common reasons why your black neon tetras’ bellies might be swollen and what you can do to help them.

1. Camallanus Worm Infection

One possible reason your black neon tetras get bloated is that they have been infected by a parasite called camallanus worm. This parasite gets stuck in the fish’s digestive system, causing inflammation and fluid buildup that swells the fish’s stomach. To get rid of parasite worms, you can give your tetras dewormer medicine like Fritz Expel-P which paralyzes or kills the worms so the fish can poop them out into the tank.

2. Overfeeding

Overfeeding is one common reason why black neon tetras get bloated. When fish overeat, their stomachs get bigger, and the extra gas gets stuck inside the body. To treat this, you could limit how much they eat until the swelling goes down or feed them high-fiber foods like daphnia or cooked peas to help them go to the bathroom.

3. Constipation

Constipation in your neon tetra can cause them to swell up and look distended. This can be caused by a number of things, such as a bad diet, not enough fresh water, or bad bacteria in the fish’s aquarium, so it’s crucial to check things out and fix any problems you find. To deal with their constipation,  you can help them by giving them high-fiber foods like daphnia and cooked peas that will help them pass waste.

4. Physical Injury

Sometimes, a fish’s bloated look is just a sign of being hurt physically, like when it hits another fish or an object in the fish tank. If your black neon tetra has cuts, wounds, or visible swelling from an injury, treat it immediately by adding 1 tablespoon of aquarium salt per 2 gallons of water to the tank. This will keep the injury from worsening and help the fish improve.

5. Eaten Too Much Garlic

Black neon tetras like to eat garlic, but if they overeat, they might get bloated. Garlic can make their stomach and intestines swell up because it irritates them. If you notice that your black neon tetras are eating more than usual or getting bigger, try giving them an Epsom salt bath in a different quarantine tank, putting the bloated tetras there, or switching their food to one that doesn’t have garlic.

6. Dropsy

All freshwater fish, like your black neon tetra, can get dropsy. Dropsy is a sign that a fish’s kidneys or gills aren’t working well. It can be caused by several different diseases that lead to an increase in water volume or a buildup of water that makes the fish bloat. You need to carefully put the fish in a hospital fish tank, ensure the water is just right for black neon tetras, add aquarium salt and high-quality food, and watch the fish closely for any signs of illness.

7. Carrying Eggs

Black neon tetra females carry their eggs until they are fully grown and ready to be fertilized. Because they carry so many eggs, they tend to have swollen bellies when they are pregnant. If they are pregnant, all you need to do is make sure your water is stable, give them good food, and keep an eye out for them so you can take care of them.

8. Swim Bladder Disease

Like most fish, black neon tetra has a small organ called a swim bladder in its stomach that controls how they float and stay balanced in the water. If their swim bladder is inflamed, the fish will have a big belly and cannot swim well. To help them, you can move them carefully to a separate hospital tank, add a tablespoon of salt per 2 gallons of water to the water, keep an eye on them, and give them food that sinks.

No 5- What To Do if My Black Neon Tetra Have Bumpy Skin

Many diseases can affect your black neon tetra and some of them are visible on their skin. Some of it can not only give them bumps, but it can also hurt or kill them. Here are some reasons why your black neon tetras’ skin is bumpy and what you need to do about it.

1. Neon Tetra Disease

Neon tetra disease is a parasite that can kill your black neon tetra if it gets it. When they get infected, cysts can form in the muscles, and the body and skin can also get lumpy and bumpy. Unfortunately, there is no way to treat neon tetra disease, but you can remove sick fish from the fish tank to keep healthy fish from getting infected.

2. Ich

Ich is another parasite that forms white spots that look like small bumps on the skin of your black neon tetra. Ich is often spread when infected equipment is moved from one tank to another without proper cleaning when infected filter media or decorations are moved from one tank to another, when infected water is moved from one system to another, or when infected plants are added to an aquarium.

3. Lymphocystis

Lymphocystis is a disease that affects fish and is caused by a virus called lymphocystivirus. When a virus gets into your black neon tetra, it gets raised bumps on the skin that is pink to white anywhere on its body, including its fins. Your tetras won’t die from this, and it will go away in a few weeks if you keep the water clean, feed them well, and keep the aquarium at the right temperature.

4. Tumors

Tumors can occur to almost any fish, including black neon tetra, and most of the time, they look like bumps or lumps under the fish’s skin. These tumors are not dangerous to fish unless they make it hard for them to do things like eat or swim. There is no way to cure or treat a tumor, but you can take care of your fish in general.

5. Dropsy

Dropsy is a condition that causes your black neon tetra’s scales to stick out from its body, giving it a bumpy appearance. It is caused by poor water quality and can be fatal if not treated quickly. To reduce the risk of this happening, make sure you clean the tank regularly and keep an eye on your fish’s environment.

No 6- What To Do if My Black Neon Tetra Have White Spots

Even though black neon tetras are pretty hardy, that doesn’t mean they can’t get sick. Some parasites can still get past their immune system and infect them; some diseases can cause white spots. If you see white spots on your black neon tetra, here are some reasons and things you can do to cure them.

1. Infected With Ich

Ich is a common parasite that can infect your black neon tetras and cause tiny colonies, which are the white spots you see on their skin. If you don’t treat Ich, it will weaken your fish or kill them. To treat ich, you can raise the temperature of your aquarium, apply ich treatment, and then watch until everything is back to normal.

2. Infected With Anchor Worm 

If the white spots on the skin of your black neon tetras have turned into thin, long white strands, it could be that they have anchor worms. The best way to get rid of the worm is by manually removing tweezers, but this might be hard because the worm’s anchor must be removed to stop secondary infection. After removing the anchor worms, you can add aquarium salt to the tank, it helps heal the wounds and kills the worm at the same time.

3. Infected With Cotton Wool Disease

Cotton wool disease is a bacterial disease that looks like a fungus that affects not only your neon tetra’s body but also their mouth. The first sign of the disease is white spots in the infected area, which soon turn into white cotton-like fuzz. To get rid of it, let your neon tetra soak in a salt bath made from 1 teaspoon of aquarium salt per 1 gallon of water for up to 5 minutes, and then put them back in their fish tank.

No 7- What To Do if My Black Neon Tetra Have An Irregular Shaped Body

Are you worried about the irregular shape of your black neon tetra? You’re not alone. Many aquarists have noticed their black neon tetras take on a strange body shape, with drooping fins and even bulging heads and stomachs. In this section, we’ll discuss five common causes for this issue and what you can do to help your fish recover. 

1. Malnutrition 

Black neon tetras require a well-balanced diet that includes plenty of protein, vitamins, and minerals to stay healthy. If your tetra isn’t getting enough nutrients from its food, it may develop an irregularly shaped body as its organs become deprived of the essential nutrients they need to function properly.

2. Swimming Stress

If your tank isn’t large enough for your black neon tetra to swim comfortably, it may become stressed and its shape can be affected over time. Tetras also need plenty of room to explore and play, so if your tank is too small or lacks hiding places, it can cause your tetra to become stressed and take on an irregular shape.

3. Parasites

Common parasites such as ich or velvet can cause black neon tetras to develop an irregular shape, as the parasite feeds from their bodies nutrients which make them weaker and less able to keep their form regular. It is important to check your tetra regularly for parasites and treat them immediately if necessary.

4. Water Quality

Poor water quality can cause black neon tetras to become stressed and develop an irregular body shape as their bodies struggle to cope with the unclean water. To keep your tank clean, perform regular water changes and monitor ammonia, nitrite, and nitrate levels to ensure the water is safe for your tetra.

5. Inbreeding

If your black neon tetra was bred from two closely related fish, it is possible that the genetic difference between them was too small, leading to inbreeding. This can lead to various deformities and health problems, including an irregularly shaped body.

6. Disease 

Certain diseases can cause black neon tetras to develop an irregular body shape and other symptoms such as fin and skin discoloration, lethargy, and appetite loss. Suppose your tetra has an irregular body shape. In that case, taking it to the vet as soon as possible is important to diagnose and treat any potential illnesses.

7. Age

As black neon tetras age, their bodies can start to show signs of wear and tear. This can cause them to develop an irregular body shape due to muscle loss and weakening of the bones. You can help to reduce this by providing plenty of nutritious food, clean water, and a suitable tank environment.

Neon Tetra Swimming in aquarium

No 8- What To Do if My Black Neon Tetra Losing Black Their Stripe

Black neon tetras have a striking black stripe that runs along their body, making them an attractive addition to any freshwater aquarium. Unfortunately, there are several reasons why your black neon tetra may be losing their black stripe, and you should know what to do about it. 

1. Stress

Like any other living creature, stress can cause a black neon tetra to lose its color. The best way to reduce stress levels in aquariums is to keep the water clean and stable and create an environment that mimics the natural habitat of the fish.

2. Poor Nutrition

If your black neons aren’t getting the right nutrition, they may start to lose their black stripe. Ensure you’re feeding your fish a balanced diet of high-quality flakes or pellets and supplementing with live food for an extra boost.

3. Disease

Fungal infections and other diseases can cause a black neon tetra to lose its color. If you notice any signs of disease, such as white spots or clamped fins, it’s important to treat the issue immediately before it worsens.

4. Old Age

As black neon tetras get older, they will often start to lose their distinctive black stripe. This is completely normal, and there isn’t much you can do about it. Still, if you notice that your fish have suddenly become much paler than usual, then it’s worth getting them checked out by a vet to rule out any underlying issues.

5. Poor Water Quality

If the water quality in your tank is poor, then this will put stress on your fish and eventually lead to loss of coloration. Monitor ammonia and nitrate levels regularly, perform water changes every two weeks and make sure you’re using the right type of filter for the size of your tank.

No 9- What To Do if My Black Neon Tetra Have A Red Spot On Stomach

Have you ever noticed a red spot on the stomach of your black neon tetra? This is a common phenomenon that can be caused by several things. Let’s discuss the five most common causes of a red spot on the stomach of a black neon tetra.

1. Stress 

Stress is one of the most common reasons for a red spot on your black neon tetra’s stomach. Black neon tetras are very sensitive to environmental changes such as water parameters, tank mates, and food quality. If any of these things are not kept in check, your black neon tetra can start to show signs of stress, such as a red spot on its stomach.

2. Fish Diseases

Another cause for the red spot on your black neon tetra’s stomach could be fish disease. Several diseases can affect black neon tetras, including Ich, Hole-in-the-head Disease, and Fin Rot. If you think your tetra might have a disease, it’s important to take the fish to a veterinarian for treatment as soon as possible.

3. Parasites

Parasites are also another common cause of a red spot on the stomach of your black neon tetra. Parasites can be anything from fish lice to worms, and they can cause a variety of issues, including a red spot on the stomach. If you think your black neon tetra has parasites, it’s important to use an appropriate treatment as soon as possible.

4. Poor Nutrition

Black neon tetras need a diet that is rich in vitamins and minerals to stay healthy. If your black neon tetra isn’t getting the proper nutrition, it can cause a red spot on its stomach and other medical issues. It’s important to provide a balanced diet for your tetra so that it doesn’t suffer from any nutritional deficiencies.

5. Genetic Defect

Lastly, a red spot on the stomach of your black neon tetra could be caused by a genetic defect. This is more common in wild-caught fish than captive-bred ones, but it can still happen. If your black neon tetra has a red spot that won’t go away, it’s best to have it evaluated by a vet to rule out any genetic defects. 

No 10- What To Do if My Black Neon Tetra Bloated

If your black neon tetra’s stomach is bloated, it could be due to several reasons. Use this list to determine if your fish might be sick and what to do with them.

1. Improper Diet

One of the major causes of bloating in black neon tetras is an improper diet. Tetras should be fed a variety of foods, with live or frozen food providing the best nutrition. Overfeeding can also lead to bloating, so ensure you are feeding your fish the right amount and not overdoing it.

2. Parasites

Another cause of bloating in neon tetras is parasites. If your fish has a bloated stomach and other symptoms such as loss of appetite, swimming abnormalities, or cloudy eyes, they could have parasites or bacterial infections that need to be treated right away. 

3. Stress

Neon tetras can become stressed easily, and this can lead to bloating. If your fish live in an overcrowded tank with poor water quality, they may be more susceptible to stress-related bloating. Ensure you provide the right environment for your fish with plenty of oxygen and clean water.

4. Injuries

If your neon tetra has suffered an injury, it can lead to bloating. Ensure you remove any sharp objects from the tank and provide plenty of hiding places for your fish to feel safe and secure.

5. Poor Water Conditions

Bloating in black neon tetras can also be caused by poor water quality or incorrect pH levels in the tank. Make sure you are monitoring your tank conditions and doing regular water changes.

6. Chemical Imbalance

If the chemicals in your tank become unbalanced, it can cause bloating or other health problems in black neon tetras. Test the ammonia, nitrates, nitrites, and pH levels every week to ensure everything is within the normal range.

7. Disease

Finally, bloating in a black neon tetra can be caused by a number of diseases, such as tuberculosis or fungal infection. If you suspect your fish is sick, contact your local veterinarian for advice and treatment options. 

No 11- How To Treat Ich In Black Neon Tetra

Ich is so common in aquariums that many fish keepers think it must be in every fish tank. That’s why it’s very important that you determine and treat it as soon as possible. Here is a step-by-step guide on how to treat ich in your black neon tetra.

1. Do A Water Change

At least a 25% water change must be done to remove some of the ich in the water. Most of the time, the black neon tetra can handle the disease better because their immune systems are stronger. You’ll only find a few infected tetras at first. But the ich is in the water in your fish tank, so the whole tank needs to be treated.

2. Increase The Water Temperature

Even after you change the water, there will still be some ich in it. All stages of ich have a protective layer around them, except for when they are free-floating, and medicines can kill them. By raising the water temperature in the fish tank to about 86°F, the ich matures quickly to reach its free-floating stage.

3. Add Flow To Your Aquarium

By giving the aquarium a little bit of flow, you can move the water around and spread the medicine all over the fish tank. This won’t hurt your black neon tetras much either, since they come from rivers and streams with moving water and like it that way. Just make sure the water flow is gentle and steady.

4. Increase Oxygenation Levels

If you raise the temperature in the tank, your tetras may become more active and need more oxygen to breathe. Also, warmer water doesn’t hold as much dissolved oxygen, so there is less oxygen for everyone. To ensure your black neon tetras don’t die from lack of oxygen, you can put them in an aquarium bubbler or air stones.

5. Apply Ich Treatment

There are a lot of medications for ich you can find at local pet stores. Usually, the dosage depends on how many gallons of water your fish tank can hold. However, when calculating the dosage per gallon, remember that substrate, decorations, and things take up space in the fish tank, meaning there’s less water in your fish tank.

6. Observe

The ich medicine might take a while to get rid of the parasites in the fish tank because other parasite stages must be free-swimming before they can be killed. Depending on the product, you may need to add another dose. After around a week or two, the ich on your black neon tetra should start to disappear.

7. Do Preventive Measures

If your fish gets ich, it can make them more likely to get other diseases and infections. This is because both stress and ich have already made your fish weak. So, after you treat your black neon tetra for ich, make sure to quarantine any new fish, plants, or used decorations to keep it from getting ich again.

No 12- Why Does Your Black Neon Tetra Have A Clamped Tail

Clamped fins are a condition that usually indicates that your fish have become stressed. Not only the tail but including the fins being clamped may be the first indication that a fish is not healthy because its behavior has changed. Here are several reasons why your black neon tetra has a clamped fin and tail.

1. Swimming in Improper Water Conditions

When keeping fish in aquariums, the water conditions are very important. Even though black neon tetras are hardy and tough fish, they still have water parameter requirements. Put them in an aquarium tank with the wrong water conditions. They will become stressed out, and they will begin to show unusual behaviors like lethargy or clamping their fins.

2. Infected With Ich

Ich is a parasite that forms white spots on the body of the fish. When your tetras get infected, they will begin to show unusual behavior, like rubbing themselves on decorations or hiding away. Before the fish gets white spots or starts to rub itself, you might notice that its fins are clamped together.

3. Dropsy

Dropsy is a serious illness in fish that causes them to get fat and stressed. This makes them feel stressed, making them lose interest in food, hide, and clamp their fins. Keep in mind that fish often die from dropsy, so make sure to treat them as soon as you notice it.

4. Sudden Changes in Water Parameters

If the parameters in the fish tank change a lot, the fish’s body can become very stressed. This can lower the fish’s immune system, cause symptoms like clamped fins, and make the fish more likely to get sick. Keep the water in your aquarium stable by keeping it away from direct sunlight, near windows, and giving it plenty of oxygen.

5. Aggressive Tankmate

Your black neon tetra is also very stressed because you put it in the same tank as an aggressive fish. If they live with other fish, make sure those other fish aren’t aggressive, so they don’t pick on your tetras. If your tetras are always being picked on, they will start to hide and clamp their fins to their sides to protect themselves.

No 13- Symptoms Of Dropsy In Black Neon Tetra (And What To Do)

Dropsy is usually a fatal illness, so it’s important to know how to tell if your fish has it. If you find it early, it could mean the difference between life and death for your fish. Here are some signs that your black neon tetra might have dropsy.

1. Swelling

The first sign that your black neon tetra is sick is its belly getting bigger. This is because when fish has dropsy, fluid builds up in their bodies. After all, they can’t get rid of the water anymore. This makes their bellies get bigger.

2. Scales Sticking Out

Because fluid builds up in their bodies, their scales point away from their skin, making them look like pine cones. Since black neon tetras are small and active, it may be hard to notice that some of their scales are sticking out. Some parts of the fish’s body may have scales that stick out, or it could have them all over.

3. Bulging Eyes

If you think your black neon tetra might have dropsy, you should also check to see if its eyes are bulging out. Eyes that are swollen show that the body has too much fluid that it can’t get rid of. The fluid puts pressure on the back of the eyes, causing them to bulge outwards, usually on both eyes.

4. Pale Gills

When a fish has too much fluid in its body, its gills could also get swollen and become pale. This is because the buildup of fluid in the body can also pop the small blood vessels in fish, meaning less blood can go to their gills. Keep in mind, however, that pale gills are a sign of many diseases in fish, not just dropsy, so make sure to look for other symptoms.

5. Rapid Breathing Of Gills

Because of the buildup of fluid, the pale gills wouldn’t normally work, so your black neon tetra has to work harder just to breathe. You can see it by looking at their gills and seeing if their gills are moving rapidly. If they haven’t become too lethargic yet, they might swim up to the water and gasp, just like when there isn’t enough oxygen in the water.

6. Loss Of Appetite

Another sign that your black neon tetra has dropsy is that it has lost interest in food. When a fish is stressed, it often won’t eat, and dropsy puts your tetras under a lot of stress. If a fish doesn’t eat, it could get hungry and weak, which makes it more likely to get sick.

7. Clamped Fins

If you see your tetra clamping their fins, this is another sign that they have dropsy. Clamped fins are a sign that your fish is under a lot of stress. But clamping fins is usually a sign that something is wrong, so look for other dropsy signs to determine if your tetras have dropsy.

No 14- What To Do With Dropsy In Black Neon Tetra

Dropsy is usually fatal, especially when it is detected late. Identifying it early will increase your chances for successful treatment. To treat them, here is a step-by-step guide on what to do.

1. Do A Water Change

Dropsy in fish is mainly caused by bacteria that are often found in aquariums. But the fish will only start to get sick once its immune system weakens. Bad water quality is one thing that can quickly weaken a fish’s immune system, so it’s often a good idea to do a water change to get rid of harmful substances and resupply the oxygen in the water.

2. Prepare A Hospital Tank

After changing the water, you need to set up a separate hospital tank for your black neon tetras so you can care for them closely. Make sure to add a heater, a filter, and either an air stone or an air pump to the tank to help the fish get better. Having a good environment for them to swim in is important for their recovery.

3. Add Aquarium Salt 

Add 1 tablespoon of aquarium salt per 2 gallons of water to their hospital tank to help reduce swelling and eliminate fluids that have built up. It can also help them heal from injuries, encourage them to make slime coats, and make their gills work better.

4. Feed High-Quality Food

When a black neon tetra is sick, it is normal for them to lose interest in food. Now that they are getting better make sure to feed them good food to help them get better even more. You can feed them flake, frozen, and freeze-dried food, as well as worms and brine shrimp, which are small and alive.

5. Treat With Antibiotics 

In local pet stores, you can find a lot of antibiotics that are made especially for bacteria that can cause dropsy. Always follow the directions for how long and how much to give your fish, and keep an eye on it for a week or two or until the symptoms disappear.


Black neon tetras may develop different problems as you take care of them. Fortunately, some of these problems can be treated as soon as you identify the root cause.  We hope this article has provided you with helpful information about common problems that your black neon tetra may have. Whether it’s swimming sideways, having white spots or a red spot on its stomach, or even dropsy, our advice above will surely help you in taking care of your fish and bringing them to good health.

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