March 14

Sarah Robertson

Why Did My Betta Fish Die?

When a pet owner discovers their beloved fish has passed, it can leave a void in the home. Here's what to do if this happens to you. It is natural for an owner of a betta fish to become attached to his or her pet over time. This can make it difficult when your betta dies.

But before you go out and get another one, you need to ask yourself ‘why did my betta fish die?’. There are many potential causes of death in betta fish, and some of them can be prevented. So, understanding the main reasons for bettas dying will help you avoid making the same mistakes in the future.

Why Did My Betta Fish Die?- Reasons and Prevention

Parasites and Fungus

Bettas can develop a parasite, which causes holes to appear in their abdomen over time. Bettas also commonly contract an illness known as fin rot, which causes your fish's fins to fall off and look raggedy. But these diseases typically cause other symptoms such as lethargy and loss of appetite before they kill a fish.

The fungus Achyla can cause a white fuzzy-like growth on your betta's body and fins, which also kills it over time. The best way to prevent these diseases is to make sure you are diligent with upkeep on your betta's tank. If your tank appears dirty or cloudy, clean it immediately.

Fungus can be prevented by keeping your tank clean, not overfeeding your fish, and making sure the water is at the correct temperature level. Many times when a betta dies suddenly it is because of these diseases or parasites.

A sudden death means that you missed something in the tank that caused this disease to develop quickly. However, you should see your fish's doctor if it dies suddenly, especially because these diseases also appear in other forms.

Choking of food

Your betta fish may have choked on food if it died. This can be prevented by not overfeeding your fish and making sure you are putting the right sized pellets in the tank.

Overfeeding is a common mistake pet owners make because they feel bad that their pet isn't eating what they put in the tank. But if you feed too much, your fish will die.

Make sure you are using the right sized food for your betta fish and not breaking up the pellets into smaller pieces to make it look like more food floated to the top of the tank.

If you do this, it is possible your betta could choke on the small pellet because they aren't used to eating such a large piece of food. Bettas are used to eating the food that falls into the bottom of their tanks, not larger pieces that float around.

Betta Water Temperature

Water Temperature

The water temperature in your betta's tank must be at between 76 and 82°F Fahrenheit for them to survive. If you accidentally keeps cold water or warm water you risk your betta dying.

If the water drops too far below that temperature or goes above it, your betta's body will not be able to regulate itself and he will die. Make sure you check the temperature of your tank frequently if this is a problem in your house.

Gasping for Air at the Surface

If your betta fish is gasping for air at the surface of the tank, this can mean that the oxygen in the water has dropped too low. If you see this, do a 100% water change immediately and make sure to turn up the filter. It is possible your filter isn't working correctly or you have overfed your fish, which has caused the oxygen to drop.

Poor Water Quality

A sudden death can sometimes be caused by poor water conditions. If your tank is dirty or cloudy, clean it immediately and make sure you are doing routine water changes. You must also make sure your filter is working correctly to remove waste from the tank because if there is too much waste in the tank, your betta will die.

If you notice a sudden death of your fish, do a complete water change and make sure to check all of these conditions before getting another betta. If you don't, you won't know what caused the fish to die and will most likely end up with the same result.


Bettas are used to eating the food that falls into the bottom of their tanks, not larger pieces that float around. Make sure you are using the right sized pellets for your betta fish and not breaking up the food into smaller pieces to make it look like more food floated to the top of the tank. If you do this, it is possible your betta could choke on the small pellet because they aren't used to eating such a large piece of food.

Fish Lice

Fish lice are very common in bettas and can result in death if not treated. Cleaning your betta's tank will also help prevent these parasites from developing in your fish's habitat.

Harassment by Tank Mates

The only other fish you should have in a betta tank is another betta. Bettas can be very territorial and will kill any other fish, shrimp, or snails that enter their space. If one of your tetras wanders into the "betta zone" it may result in death, even though you didn't do anything wrong. If you want to keep another fish in bettas tank, You need to have a bigger tank where the other fish have plenty of room.


If you move your betta to a new tank or change the decorations in his habitat, it can be very stressful for your pet. Bettas are used to their homes and change causes them stress which results in health problems, including death. If this happens, don't be surprised if your betta dies suddenly.

Natural Death

Sometimes bettas die naturally even if all of their needs are met. It is also a good idea to keep an eye on your other fish in the tank to see if they are exhibiting any of these symptoms. If they do, you have an issue with your tank that needs to be fixed immediately.

If you want your betta fish to live the longest and healthiest life possible, keep it in a filtered tank that is kept between 76 and 80 degrees. Bettas are very sensitive and it's not uncommon for them to pass away after a couple days of happy living.

If your betta dies suddenly and for no apparent reason, it's most likely the result of the problems listed above. However, if you want to prevent this from happening, just keep up with basic tank maintenance and watch out for signs that something is wrong.

Issues Beyond Your Control

When you get a new fish home, you have no idea if he's sick. You have no way of knowing whether he has some hereditary condition that will kill him regardless of what you do. You may take a brand-new puppy to the veterinarian for testing for such problems, but there is simply no way to do so with a little fish.

If you feel that you have done everything correctly and yet your fish nevertheless dies, don't beat yourself up. Yes, it's always a good idea to review your fishkeeping techniques and see whether you could have done anything differently. However, keep in mind that it may not be entirely your fault.

Furthermore, if you've done everything wrong and your betta has lived for years, don't assume doing things correctly doesn't matter. Some fish can live unhealthy lifestyles and reach old age. And some may die young in unfavorable, unheated, unsafe, or clean water despite living a healthy life. The rest is luck.

Common Betta Fish Diseases

Common Betta Fish Diseases, Symptoms, Causes and treatment

Fin and Tail Rot

This condition affects betta fish's fins and tails. It might be caused by germs or fungus. The fins and tail appear to degrade or discolour as a result of decaying.

Betta fish fins and tails can get ragged and frayed, but if the rot spreads and becomes cloudy or pink, it's most likely fin rot. It might be induced by poor water conditions or a bacterial illness, so look for ammonia, nitrite, and high nitrate levels in your water.

Keeping the aquarium or fish's living conditions clean is one way to avoid it. It can be treated with medications containing antibiotics, such as trimethoprim, erythromycin and sulfadimidine.


Dropsy is a term used to describe a betta's belly is swollen with fluid. This may be the result of a bacterial infection or poor water quality that stresses the betta, causing its organs to fail and release fluid into its belly.

Outward-sticking white scales and sunken eyes are other symptoms of Dropsy.

Keeping the aquarium clean is one method of avoiding bacterial infection. Feeding fish with vitamin-rich foods is also effective in preventing it.

Dropsy can affect both wild and domesticated betta fish. It's essentially the final stage of a betta fish in which its organs begin to fail, causing it to bloat with fluid. This may be caused by a number of reasons including:

Poor water quality (ammonia toxicity, nitrite toxicity, high nitrate levels)

Lack of Proper Diet (a betta's digestive tract may fail if it's only fed freeze-dried or frozen blood worms)

Genetic issues (the betta may be born with weak organs that are prone to failure)

There is no known cure for dropsy, but medications like Betta Revive can help with the problem. Betta fish that have Dropsy are not often able to survive.

Columnaris  (Fur Coat)

Columnaris is a bacterial infection that causes cotton-like white or gray patches to appear on your betta's mouth, lips and barbels (whiskers). It can be treated with antibiotics if caught early. Because there are so many different types of bacteria floating around an aquarium, it's easy for even the cleanest fish tanks to become infected.

The sickness can be prevented by treating open wounds and fungal infections. It can also be prevented by avoiding factors, such as limited oxygen, water hardness and overcrowding in the aquarium.

Columnaris can be treated with antibiotics such as penicillin or tetracycline if caught early. Despite the fact that this bacteria is easily transferred from tank to tank, it's advised that you destroy your tank and everything in it if one betta gets columnaris. This will stop the infection from spreading and protect other fish in your home. If the infected fish is not treated, it can die in less than 72 hours.

Hemorrhagic Septicemia (HS)

A common name for this disease is redmouth, which refers to the bleeding that takes place in the fish's mouth and eyes. This can be transmitted through parasites like flukes and nematodes. It can also be transferred through wounds caused by aggression or physical damage to your betta's mouth. If you notice that your betta has an open wound, immediately separate him from any other fish.

The infection can be prevented by cleaning the aquarium to destroy Yersinia ruckeri, the microbe responsible for the disease.

Antibiotics such as ampicillin can be used to treat hemorrhagic. The fatality rate is low because this sickness is curable, which implies that it may be treated.

Velvet Disease Betta

Velvet Disease (Oodinium)

Betta fish are particularly vulnerable to velvet disease also called gold-dust, rust and coral disease. It is a fish disease caused by dinoflagellate parasites of the genus Piscinoodinium. The disease makes afflicted organisms appear dusty, brownish-gold and can also have black spots or marks allover the skin causing a color loss.

The disease may be contracted in several different ways, including:

Being exposed to a betta who is infected with velvet

Being exposed to an environment containing the parasite's developmental stage

If your betta has been exposed to velvet disease, it's important that you monitor his behavior and condition closely. If he stops eating or appears listless, immediately isolate him from the rest of your bettas. This way, other fish aren't exposed to the parasite.

It is highly contagious, and although it can be cured entirely with Bettafix Remedy, it may be treated. This medicine manufactured by Aquarium Pharmaceuticals, include sodium chloride, copper sulfate, acriflavin, formalin, sulfa 4 TMP, methylene blue and malachite green.

Treatment includes improving water quality and isolating your betta from other fish. Bettas who recover may show no signs of the disease for several months – and then suddenly die without warning. If you think that your betta is ill, it's best to consult with a veterinarian who specializes in fish before trying anything yourself.

Also, always keep your betta's living environment clean and avoid overcrowding. This will help the active fish stay healthy and ward off any infections that might otherwise be contracted from exposure to other sick fish.

It's also important that you only purchase betta fish that are quarantined by your fish store. If you can, don't ever release your betta into local waterways. This is because the bettas who live there already have their own natural habitats and food sources to take care of, so introducing another predator can put them in danger. Adding another fish to the environment can also disrupt the area's delicate ecosystem.

Popped Eye

This disorder usually affects young Betta fish. It is caused by a bacterial or fungal infection in the eye, which then ruptures due to excess fluid pressure. After one of his eyes pop, your betta will probably be blind in that eye for the rest of his life even after you treat him.

Pop Eye usually is a sign of an illness and may be avoided by avoiding infections in the tank. First signs of the disease include a cloudy-white film over your betta's eyes. The cloudy film will expand, and eventually one or both of its eyes pop from the pressure caused by excess fluid buildup.

Fortunately, pop eyes can be treated if discovered early enough. The condition may be cured with antibiotics such as tetracycline. As a result, the majority of fish that have pop eye ultimately recover.


It is also known as cloudy cornea. This disease causes white films on the eyes. It is usually caused by a parasitic infection or poor water quality. By enhancing the quality of water by using a water conditioner, this disease can be prevented.

Eyeclouds is an advanced stage of the disease called Pop Eye. His popped eye will eventually clear up with medication and proper care. It can be treated by antibiotics such as Metafix and Fungus Clear.

Fish Fungus

It's a fungus that spreads from one fish to another. The affected betta has cotton-like growths, white fuzz films, slime, or white lumps and bumps on its skin.

Poor water quality and lack of proper care is the leading cause of fish fungus because the bacteria thrives in unclean conditions. Properly cleaning & maintaining your betta's tank can prevent him from catching this disease.

Antibiotics such as Methylene Blue and Fungus Clear can cure fish fungus. The sickness can become fatal if it is not treated early enough.

Ich/Ick, and Popeye

Bettas can contract all three of these diseases by being kept in unclean water. Poor water quality is the leading cause of all of them because it allows bacteria to thrive.

Ich also known as White spot is a contagious skin infection that causes white dots, rings, lines, or spots on the belly, fins, tail, gills, and other areas of the betta's skin. It may be prevented by changing and conditioning the water on a regular basis, as well as adjusting variables like ammonia, pH, nitrites, and dissolved solids.

The illness can be treated with a salt bath or Fish-zole. Using Ich-X another best way to treat this illness. If treatment begins early, it is quite simple to manage the illness.

Popeye is another illness that causes a fish’s eye or eyes to bulge or appear swollen. A ring or splotches of white may sometimes be visible around the eye. Its symptoms can also include a cloudy or red and irritated eye.  If your betta fish has this disease, it is best to observe the fish and look for other stress or illness symptoms.

Figuring out what’s causing the popeye can help you quickly find a cure and solve the problem. Popeye, when left untreated, can result in a variety of health problems, including an eye rupture and blindness, as well as the fish's death.

The treatment for betta fish popeye is determined by the reason. If it is due to an injury,vThe most effective cure is to relocate the betta to a quiet, solitary aquarium and allow the eye to heal independently.

If the popeye is caused by an infection, you may require a popeye medicine. Popeye medicines such as antibiotic or antifungal drugs can help to treat the condition. Although some medications might help to cure the popeye, the infected fish may also have an internal problem which cannot be treated.

Anchor Worms

Anchor Worms

The tail or fins are susceptible to this parasitic condition. The afflicted regions appear red and engorged, with protruding worms and strings of slime.

Poor water quality is the leading cause of Anchor Worms because the parasites thrive where there's excessive amounts of decaying matter. This  bacteria causes the worms to infest your betta's body, which looks really gross & can be fatal if it enters his bloodstream.

It can be avoided by treating the infected fish promptly, as well as keeping the water clean.

The illness can be treated with several antibiotics, such as Methylene Blue and Parasite Clear. If it is not treated promptly, the sickness can progress to a deadly condition.

Hole in the Head (Hexamitiasis)

Betta fish with a hole in the head have an abrasion on the top of their heads that resembles a pinhole or white fuzz. It is usually a secondary infection in fish that are already afflicted with fin rot.

Poor water quality is the leading cause of Hole in the Head because the parasites thrive in dirty tank water where there's excessive amounts of decaying matter. Cleaning carbon off water is one way to prevent this infestation.

If the fish is suffering from a parasitic infection, it may be treated with Parasite Clear, an antibiotic that kills parasites. If the sick fish isn't treated promptly, it will most likely die within a few days. 

Swim Bladder Disorder (SBD)

It is known as flipover. This disorder is caused by an infection of parasites, bacteria, or fungus that's obstructing your betta's swim bladder. The fish with this condition is forced to float on the surface of the water.

The sick fish swims sideways or upside-down and may even rest at the bottom of the tank. Constipation, poor water quality, and swollen organs are the other causes of this disease.

This disease can be prevented by maintaining clean and fresh water, avoiding overstocking and feeding the fish with the right amount of fresh and fiber-rich foods.

The treatment for swim bladder disease is to add aquarium salt, increase the tank water temperature, restrict feeding for a few days, and feeding cooked peas.

Betta Tumors

Betta tumors are benign growths or lumps in the fish's skin that are generally cancerous. They primarily affect the reproductive organs, gills, tail, and abdomen, and are caused by genetic aberrations and viral infections.

The tumors can be treated by providing the fish with nutritious food, cleaning the tank on a regular basis, treating other ailments, and keeping cancer-causing chemicals out of the tank.

Gill Flukes / Gill Worms

Gill flukes are parasites that live on the gills and occasionally on the skin of fish. They cause hypoxia by causing gill filament hyperplasia. Rapid respiratory movements, fins held against the body, and flashing are all signs of it..

As flukes are often the root of ulcers and other secondary infections, treat for flukes before treating with antibacterial or antifungal medications. A number of treatments are available for flukes, those containing Praziquantel are the most effective.

Depending on how severe the infestation is, visible symptoms of improvement may typically be observed after 2-5 days. Complete recovery might require up to two weeks, with the main portion spent recovering.

Scoliosis (Bent Spine)

If you observe that your betta's spine is curved, it's most likely due to the fact that his or her organs have swollen and bent the structure of their spine, or because the spine itself has become diseased. It is mainly caused by nutritional deficiencies (vitamins C and E and some amino acids).

Betta Fish Tuberculosis

Fish tuberculosis is a chronic bacterial disease that can be fatal, especially if it isn't treated promptly. The bacteria are typically contracted through the mouth, often from other fish who may have come in contact with contaminated water or another sick Betta. Additional causes include stress and malnutrition due to bullying by tank mates.

The treatment for this illness entails rapid diagnosis and treatment in order to avoid irreversible internal damage. Treatment with antibiotics is the only option when it comes to this disease. If left untreated, even if your betta initially shows signs of improvement, he or she will eventually die from the infection.

Final Thoughts:

Fish owners can maintain bettas in excellent health with the information above. Behavioral issues, such as stress, tiredness, and poor appetite, can develop in some fish. You shouldn't be concerned about these short-term problems, particularly if your fish is new to the aquarium.

Betta fish may also have fading color or a change in color, and they can develop bubbles and blobs on their bodies as a result of these issues. These situations may be handled by adjusting and conditioning the water on a regular basis, as well as tweaking variables such as ammonia, pH, nitrites, nitrates, air, water hardness,.

Betta fish might be the most beautiful and elegant fish in the aquarium industry, but they can also be quite resilient if their environment is suitable. However, it's always best to take preventative measures than wait for your betta to get sick: After all, prevention is better than cure!

Sarah Robertson

I am a passionate blogger who also happens to be a fish keeping enthusiast. Writing about my hobby is something that I absolutely love to do, and it's no secret that my chosen topic is always centered around fish keeping.

Sarah Robertson

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