Why Did My Betta Fish Die? 20 Weird Reasons

Eye-catchy colored betta fish with their downwards swooping long tails and gorgeous fins must be a unique addition to your tank. But, it may come as a shock when you suddenly discover your betta fish dead in the tank. So, you must be questioning yourself- why did my betta fish die?

Incoordination of environmental parameters, incompatible tank mates, wrong diet and feeding schedule, and other stress factors can be reasons for the death of betta fish. Despite taking proper care, you can still lose your betta fish because of their hereditary problems, old age, or other unknown issues.

But, you need not become stressed searching for the possible reasons for your betta fish to die. In this article, I’ll write down details about why your betta fish may die.

Also, I’ll shed some light on the prevention of premature death, enhancing the life expectancy of your betta, and related queries. So, I’ll urge you to go through this entire article if you want to save your betta fish from an early death.

What Is The Life Expectancy Of A Betta Fish?

The average lifespan of these exquisite betta fish is around 2-5 years in the wild. In captivity, their longevity is largely dependent upon several factors. If you take proper care of betta fish, these bettas will accompany you for around 2-4 years.

Why Did My Betta Fish Die Suddenly?

Although all livings are mortal, there remain some factors behind the early loss of lives. If you lost your betta fish, you should check out the following probable reasons. Also, these potential causes of death will help you understand the loopholes of your betta fish upbringing in captivity.

So, let’s go through the following list without any further ado.

1. Lack Of Acclimatization

After buying a new betta fish from online or local stores, the very first thing that you need to do is to acclimate your betta. The most common reason for losing betta fish is the lacking of proper acclimatization, after introducing it to the new tank.

Many new owners tend to put betta fish in the new tank straight from the transportation bag. This act may put your betta into a great shock due to facing a sudden exposure to the new environment.

Without acclimatization, your betta fish may not adjust to the different pH and temperature of the new tank water. Because of being hypersensitive to the environment, your newly brought betta fish may die lacking acclimatization.

How Long Should Water Sit Before Adding Betta Fish?

To make sure not to stress your betta, you should let the water sit before adding your betta into it. 15-20 minutes can be sufficient to keep the water sitting.

If you treat the water, you must not add the betta instantly on the next day. However, it’ll be best in case you let the whole setup of the tank with water sit for 24-48 hours before introducing your betta fish.

Want to get a printable version of this infographic? Click here! [If you want to use this infographic on your website, please link back to this post as the source!]

2. Too Small Tank: Can A Betta Survive In A Small Tank?

These beautifully colorful betta fish are highly active and playful. Hence, these fish require ample space to play and move around.

An ideal tank for keeping a single betta fish should be at least the size of five gallons. If your betta fish do not find much room for themselves, they will not survive long in a small tank.

Small tank gets contaminated fast by waste. Besides, when you add additional décor items, filters, and other essential things, the tank will get more congested. It will narrow the room for betta fish.

As a result, the usual activities of betta fish may get hampered. It puts affects their health. So, keeping betta fish in a small tank can dramatically reduce the average lifespan of betta fish.

how do you know if a betta fish is going to die infographic. Shows most common signs before betta fish die including lethargy, less swimming, fading colors, loss of appetite, etc.

Want to get a printable version of this infographic? Click here! [If you want to use this infographic on your website, please link back to this post as the source!]

3. Overstocked Tank

If your betta fish died recently, you should check out whether the tank was overcrowded or not. Overstocking or over-crowded tanks is another top-listed reason behind the sudden death of betta fish.

The betta fish tank may get overstocked when you add too many décor items. If the tank size is small, adjusting the essential devices can shorten the space too. Also, keeping a huge number of tank mates without considering the tank size will overcrowd the tank.

In an overcrowded tank, the betta fish will lack the proper amount of oxygen in the water. Besides, your betta fish will not have enough space to move freely. So, it may put them under stress.

Considering all indirect effects, an overcrowded tank will cause slow growth and weak immunity of your betta fish. So, your betta fish will get often sick. As a result, your betta fish will die before reaching its full lifespan.

4. Poor Water Condition

Since betta fish thrive in water, changes in water parameters can lead your betta to die. If you’re wondering why your betta fish died, poor water condition may be one of the reasons.

See also  Betta Fish Poop: What Secrets It Holds?

You might know that the ammonia and nitrite level should be 0 ppm in the water of the betta tank. On the other hand, the wastes of betta, uneaten foods, and decaying leaves constantly add toxins to the water. Also, the water quality gets poor when it is not cycled or changes regularly.

Being sensitive to water quality, betta fish can not survive in poor water conditions. These fish becomes more susceptible to diseases in such condition. Besides, if the water contains additives and chemicals, your betta fish will die.

5. Low Water Temperature

If you don’t know yet, let us remind you that betta fish like to live in warm water. Although these fish may not instantly react to cold water, they’ll eventually slow down their activity.

Since betta can not generate heat like warm-blooded animals, these fish require a strict range of temperature in their habitat. If you want to keep your betta healthy and happy, you should maintain 70-80 degrees Fahrenheit in the betta tank.

On the other hand, the room temperature where the betta tank is kept may not be as warm as to keep the water 70-80 degrees Fahrenheit hot. Also, the temperature may drop down at night time. Hence, adjusting a heater can help keep the water warm in the betta tank.

So, not keeping a heater can be a big reason for the low temperature of the tank water. As a result, the immune system of betta tends to become weak.

Such is because cold water does not contain adequate oxygen levels. In addition, these fish may become sick easily because of losing immunity due to living in cold water. So, low temperature or not adjusting a heater may be the reason why your betta fish died suddenly.

How Cold Is Too Cold For Betta Fish?

The safe lowest temperature is 75 degrees Fahrenheit for betta fish. If the temperature goes below 75 degrees Fahrenheit, it’ll be too cold for betta fish. Although your betta fish can survive below 75 degrees Fahrenheit, these fish will not thrive happily in such cold water.

6. Unreliable Heater

Sometimes, keeping a faulty or unreliable heater may cause the death of your betta fish. Such a heater may become excessively heated up which increases the water temperature too high. If the temperature goes above 90 degrees Fahrenheit, it’ll kill your betta. 

On the other hand, the tank water will not be enough warm if the temperature of the air is not hot. Besides, the poor airflow of the heater may cost the lives of your betta because of not keeping the constant range of temperature.

7. Not Cycling The Tank

You must be aware that betta fish produce nitrogenous wastes like all other fish. From these nitrogenous wastes, harmful ammonia and nitrite are produced.

On the other hand, these end products are highly toxic to the betta. Besides, there will be lacking oxygen in such uncycled water.

For this, you need to either make small water changes or add an aquarium filter. When you do not regularly cycle the betta tank, your betta fish will die. You can also check out here whether your betta needs a filter or not.

8. Dirty Tank

Not cleaning the betta tank regularly can cause premature death of betta. If you do not make a regular cleaning, there will be the growth of algae and moss.

Thus, the tank water will be cloudy and dirty. Also, there will be lacking oxygen. If your betta dies due to poor water conditions, the dirty tank can be the invisible reason behind this.

9. Shock Of Sudden Water Change

When you change the water in large shares, it’ll bring a huge change in the temperature and parameters of the water. Your betta fish may not get adjusted to the new parameters of the water.

So, when you introduce your betta to new water, it may cause a sudden shock. The experts termed it an osmotic shock. As a result, this shock might make your betta stressed which results in their death.

How Often Should I Change My Betta Fish Water?

You should change around 10-20% of the water every week. It is suitable for larger tanks. If the tank is smaller than 3 gallons, you may need to change around 40-50% water change daily.

Click here to know how long can a betta fish go without a water change.

10. Incompatible Tank Mates

Betta fish are pretty smart and curious creatures in nature. Besides, the experienced owners refer to these fish as aggressive and playful fish. So, while adding tank mates, you must keep the size and temperament in mind.

Several kinds of tank mates are considered incompatible with betta fish. For example- the fish with large fins, predatory fish, territorial fish, and top occupying fish are wrong tank mates for the betta.

When bettas live with such tank mates, they may remain in stress. Also, those incompatible tank mates may injure your betta fish.

The larger tank mates might consume your smaller betta too. So, if you wonder why your betta died, you may look for their incompatible tank mates as guilty.

Which Tank Mate Should You Avoid With Betta?

Several fish and other creatures are incompatible with betta fish. Such as goldfish, Minnows, Dianos, tiger barbs, Nippi barbs, crayfish, gouramis, cichlids, dwarf pea, guppies, rainbow sharks, etc.

11. Poor Diet

The beginners often believe in the myth that betta fish can survive upon plant-based food. But, shockingly, these betta fish are carnivores. Hence, they demand varieties of protein-based diets, frozen or live foods, high-quality pallets, flakes, etc.

Sometimes, the betta fish owners remain so indifferent to their betta that they repeat the same diet. Because of having no variation in diet, the pet betta may not get the required nutrition. Due to a poor diet, your betta fish may suffer from malnutrition.

As a result, these betta fish are susceptible to diseases that may lead to their death. So, the owners often do not find any proper reason for why their betta died.

Then, you may investigate whether the betta was having a poor diet or not. Check out this betta fry feeding guideline: how often to feed betta fry?

How Long Can Betta Go Without Food?

You can keep a fully fed betta fish for 10-15 days without food. But, you should maintain regular feeding with adequate quantity. Otherwise, slow starvation may stress your betta.

12. Overfeeding

It’s an instinct of betta to consume the available extra food. On the contrary, there is a saying that the stomach of betta is as large as the size of their eyes. So, their digestive tract is so short that overfeeding may lead them to death.

The overfed betta may suffer from constipation, obesity, stress, etc. It will put a negative impact on their health. As a result, your betta fish will die because of overfeeding.

If you have further confusion, you can check out this write up- can you overfeed a betta fish?

See also  How To Clean Fish Tank After Betta Dies?

13. Holiday Or Weekend Fish Food Block

Sometimes, the betta owners fear leaving betta without food for a week or more. Hence, they rely upon holiday or weekend fish food block whenever they go out from home. But, this fish food block might be the reason for the death of your betta.

As the holiday fish block releases slowly, it can pollute the tank water fast. Also, it’ll lead to the malfunction of your betta. Thus, your pet betta will die.

14. Wrong Diet

Several risky food items can kill your betta. These include citrus food, fibrous fruits, and vegetables, plant roots, carbohydrate-based food, etc. Moreover, expired food is also fatal to the betta. So, the wrong diet can be the significant cause behind the death of your betta.

15. Faulty And Edgy Décor Items

Décor items boost the well-being of betta fish by adding a naturalistic vibe. But, the sharp and edgy décor items can injure your betta. If any of the décor items have a rough surface, your betta fish will get hurt. When the wound gets infected, the betta fish may die too.

16. Being Stressed

Being stressed is another probable reason for the sudden death of betta fish. Betta can get easily stressed out because of being sensitive to environmental conditions.

The concerning impact of stress is that it makes the immune of betta low. Hence, a stressed betta gets affected by diseases more than a healthy betta. In short, stress reduces the average lifespan of betta fish.

Several stress factors are-

  • Aggressive tank mates
  • Tapping on the glass
  • Extreme temperature
  • High level of ammonia, nitrite, etc.
  • Strong current of the filter
  • Cold water
  • Shifting to another room or building
  • Huge water change

17. Jumping Out Of The Tank

When your betta tries to jump out of the tank, there must be something wrong with the water condition. Generally, these fish want to leave the tank when the water quality becomes poor. Besides, being stressed may encourage your betta to do such an act.

On the other hand, betta may survive the highest 1-2 minutes without water. Also, there are risks of getting injured when they fall onto the floor. So, jumping out of the tank can be one of the most unfortunate reasons for the death of your betta.

18. Diseases

Your betta fish might die if it does not get recovery from diseases. These fish are prone to fungal, parasitic, bacterial, and viral diseases. Some common betta fish diseases are fin and tail rot, mouth fungus, fish fungus, swim bladder disorder, dropsy, ich, popeye, etc.

In addition, your betta may get wounded due to various reasons. If the wounds get infected, the infection may take the lives of your betta.

19. Poor Heredity

Betta with poor genetics or heredity can not make a longer lifespan. These kinds of betta fish always tend to remain sick and prone to diseases.

You can also face the same when you buy betta from large-scale breeders. Hence, no matter how much hard work you do for betta upbringing, betta with poor heredity or genetics faces premature death.

20. Old Age

No matter how much you take good care of your betta, this pet fish will leave you someday. The average lifespan of betta is around 2-4 years. If your betta crosses this milestone, it may die due to reaching its old age.

Why Did My Betta Fish Die Overnight?

Have you ever faced such a tragic incident where your betta fish died overnight? You must be shocked due to losing the newly arrived betta under your responsibility.

But, it may not be your fault at all. Again, there can be a few lacking knowledge that may lead to this unfortunate accident.

Let’s see what can cause your betta fish to die overnight.

Rough Travel

If your newly arrived betta fish died overnight, it might be the effects of rough travel. A long journey might make your betta stressed and sick. In consequence, your betta died overnight without giving you much time to get a good bonding.

Have a look at this article if you want to transport your betta on an airplane.

Sick From Beforehand

When you buy betta online from unreliable sources, there remain possibilities of getting sick betta fish. So, it would not be your fault when the dead betta was sick beforehand.

New tank Syndrome

When you start up a new aquarium with fresh water, new tank syndrome can be seen after introducing betta into the tank. In this condition, the nitrite level rises quickly which is fatal to the betta.

However, if you want to move your betta fish to a new house, you can go through this article- how to move betta fish to a new house?

Rapid Water Change

You might be noticing your betta being active and healthy. Then, you are bound to be shocked to find dead betta fish the next day. When you make a rapid water change, your betta might die overnight. Such is because betta fish can not adjust to the sudden changes in parameters in water.

Why Did My Betta Fish Die In A Week?

Generally, betta fish die due to incoordination of the environment in captivity. If your betta fish die in a week, there may remain several reasons. Such as inappropriate water parameters, low temperature, hot water, overfeeding, inadequate feeding, wrong tank mates, stress, etc.

Why Did My Betta Fish Die At The Bottom Of The Tank?

When betta fish die, they will sink to the bottom of the tank. The air in the bladder of the dead betta fish gets dissipated since the decomposition process gets started. When the swim bladder of the dead betta degas, the betta will sink. That’s why your betta fish die at the bottom of the tank.

What Are The Signs Of A Dying Betta Fish?

In identifying a betta fish nearing death, look for signs like lethargy, slow reaction, and fading color.

Mary McCauley, a seasoned betta fish rescuer, adds, ‘Watch for difficulty in swimming, changes in breathing, appetite loss, weight changes, and alterations in poop and fin appearance. Early intervention, such as testing water parameters and consulting experienced keepers, is crucial.’

Recognizing these symptoms early can be vital in taking corrective measures to save the fish.

If your betta fish is dying, it will show some signs from beforehand. Also, it’ll be easier to save your betta fish when you recognize those signs. So, let’s go through the following list to get enlightened more.

1. Lethargy

Lethargy is a common sign of sick or stressed betta fish. If your betta fish is dying, it will become weak. Also, it may tend to hide.

Otherwise, naturally betta fish are super active fish. You can always notice them playing and swimming around in the tank. So, you should consider this when your active betta fish suddenly gets lazy and lethargic.

See also  Do Betta Fish Float When They Die?

2. Slow Reaction

If your betta fish is still young but shows a slow reaction, there must be something wrong. You should notice the response of your betta when you give them food. Besides, these fish tend to remain curious when you tap the glass or attract their attention. The sick or dying betta fish show such a slow reaction.

3. Swollen Belly

Swollen belly can be a sign of dropsy. Although it is not a disease, this bacterial infection can cost the life of your betta fish. Usually, poor water quality and high ammonia or nitrite level in the water can cause dropsy.

4. Less Swimming

Naturally, betta fish are not fast swimmers. But, the dying betta fish remain too exhausted to swim. You should notice whether your betta fish swim less than usual times.

5. Laying Down

Laying down at the bottom doesn’t necessarily mean your betta is dying. Your pet betta may sleep or rest while laying down. But, if there are other signs of a dying betta, laying down at the bottom can be a terrifying sign. You should check out whether your betta has a good appetite or not.

6. Fading Color

If your betta fish is old, losing color may not be a matter of concern. But, fading or losing the color is a horrific sign of a dying betta. You should notice if your betta is turning dark or white. When your betta suddenly loses color, it may be seriously ill or dying.

7. Hunched Back

If your betta has bent back or hunched back, its internal organ may be damaged. In such cases, the damaged organ becomes swollen and the spine becomes severely infected.

Also, it can be a sign of having a tumor. If your sick betta is not treated soon, it will die.

8. Clamped fins

Usually, betta fish attract us with their colorful, unfurling tail and fins. When your betta fish has clamped fins, there may have some issues with the water quality. Besides, discoloration with clamped fins is a serious symptom of fin rot.

However, clamped fins are not a sign of any specific disease. Rather, it gives you hints of underlying problems of incoordination of the tank. So, you can start solving the problems considering the clamped fins as a big sign of dying betta.

9. Scratching Or Rubbing

You might notice that your betta is rubbing or scratching its back or sides on the objects of the tank. It is not a healthy sign of a fit betta.

10. Frequent Breathing

Another common sign of a dying betta fish is frequent breathing. You might notice your betta fish grasp air coming to the tank surface. Also, this act happens for various reasons.

Your betta may be stressful. Also, the water condition of the tank may be poor. Besides, overcrowding and diseases also cause frequent breathing of betta.

11. Loss Of Appetite

A dying betta tends to lose interest in food. Usually, betta fish are voracious eaters. When your voracious pets suddenly become lazy to pick foods, there must be a deadly reason. So, you must become concerned when your betta fish loses its appetite. 

12. Physical Symptoms

You can look for the physical symptoms if your betta is dying. The dying betta may have cloudy eyes, raised scales, white spots, swollen gills, etc.

How Do You Revive A Dead Betta Fish?

It’s impossible to revive a dead betta fish. When any creature dies, all of its organs must have stopped functioning.

Being affectionate, the betta owners might want to revive their dead betta fish like choking dogs or cats. Sometimes the lives of dying livings can be brought back by doing CPR.

But, you can not perform this technique on the body of the betta. Their internal systems of organs do not support this technique.

Moreover, this is pretty hard to spot when your betta fish is passing out. Such is because the betta slows down the breathing rate gradually. Hence, you can’t bring back a dead betta fish. But, you can revive a dying betta fish.

How To Save A Dying Betta Fish?

If you notice the signs of a dying betta fish, there will be chances to save the betta fish. Let’s see how you can revive your dying betta fish.

Recognize The Problem Or Illness

The very first thing you need to do is recognize the problem. You should discover the reasons behind the signs of your dying betta. It can be the result of any disease. Also, it may be the outcome of any incoordination of the betta tank.

Treating Illness

I’ve made a small list, including the diseases, symptoms, and treatments. You should figure out the illness by matching the symptoms. Further, take proper action and provide treatment according to the diseases.

Diseases  SymptomsTreatment
Tail And Fin RotThe edges of fins and tails turn black. Holes in fins and tails. Lastly, the fins and tails start melting or disappearing.Several medications can help your betta which is suffering from this disease. Like- Ampicillin, Tetracycline, Erythromycin, Sulphadimidine, Hikari Revive, etc.
HaemorrhagicBleeding inside the mouth and eyes of bettaAdd Ampicillin into the water.
Swim Bladder DisorderSwollen bellyLet the sick betta fast for some days. Besides, increase the water temperature.
IchWhite spots all over the body. Loss of appetite.Rise the water temperature. You can provide a salt bath. Otherwise, you may use malachite green or Ich-X.
VelvetDiscoloration, rusty and scaly skin, clamped fins, scratching, and loss of appetite. Treat with API Body Cure. Improve the quality of water and living conditions.
Fish FungusCottony patches over the body. White lumps on the skin.Use antibiotics like Methylene Blue.
Pop EyeSwelling on eyesUses Tetracycline.
Anchor WormsAttack on fins and tails. Swollen and red affected areas.Methylene Blue
ColumnarisFray fins, white and cottony growth on the mouth, breathing difficulties, and faded skin.Treat with Oxytetracycline, TMP Sulfa, Sulfa 4 TMP, etc.

Isolate The Sick Betta

If there are multiple tank mates with a betta, you should isolate the sick betta. Otherwise, the disease may spread to other animals.

Disinfecting The Betta Tank

Firstly, you should transfer the dying betta to a safe place. Then, you need to empty the tank by removing the water, plants, gravel, and all other materials.

Keep the tank materials and décor items aside in a bleach solution. Along with the tank items, you have to disinfect the tank too. Rinse the tank with a bleach solution and let the solution stay for 10-20 minutes. Afterward, you must wash the tank several times with clean water.

Condition The Water

If your betta is dying, you must check out the water quality for once. There are great chances that your betta is suffering due to inappropriate water parameters. Hence, you should change the water and condition it.

You can use aquarium salt, fungus preventative, or other required ailments to treat the sick betta fish. Make sure to test the tank water.

Modifying Feeding Habits

You should provide the right diet in appropriate quantity. If your betta suffers from swim bladder disorder, you should not give food for several days.

Later, you can give cooked peas. Besides, do not forget to remove the leftover foods.

How Can You Prevent Your Betta Fish From Dying?

There is always room for improvement when you want to enhance the lifespan of your pet betta. If you want a long time to accompany your pet, you should take some effective steps.

 Let’s see how you can prevent your betta fish from premature death.

  • Buy healthy betta fish
  • Choose a large tank
  • Introducing new water after acclimatization
  • Keep the water parameters ideal
  • Cycle your betta tank regularly
  • Removing Stress Factors
  • Keeping the ideal temperature
  • No overfeeding
  • Ensure quality diet
  • Remove aggressive tank mates
  • Choose the right filter
  • Improve Living Conditions

Final Words

I hope this article enlightened you elaborately about the reasons for the premature death of betta. Also, you must have learned about how to save your dying betta. So, you should consider these preventions so that your bettas may not leave you early.

Muntaseer Rahman

About Author

Hello, I’m Muntaseer Rahman, the owner of AcuarioPets.com. I’m passionate about aquarium pets like shrimps, snails, crabs, and crayfish. I’ve created this website to share my expertise and help you provide better care for these amazing pets.


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