Why Is My Betta Fish Not Eating? (All Reasons & Solutions)

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If your betta fish is not eating, you should be concerned. It is usually a sign that one or more things are wrong in your aquarium.

If you don’t get in front of the problems, you could lose your betta. That would be sad because bettas are beautifully colored fish representing more than 1,000 years of fish keeping.

There are many reasons why bettas stop eating. The good news is that with some knowledge of betta fish needs and preferences, most of them can be fixed by you.

But don’t just go making random changes to your betta’s environment. Read this article first to spot the signs as to why your betta has stopped eating and what you can do about it.


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Betta fish, commonly known as Siamese Fighting Fish or by their Latin name of Betta Splendens, is one of the first fish new aquarium keepers encounter. They are extremely popular because of their bright colors and long, wavy fins.

They are found widely throughout Southeast Asia. Bettas have been kept for more than 1,000 years and were originally bred for aggression and fighting. They first appeared in the West in the late 19th century, and within decades became one of the world’s most popular ornamental fish.

Although they still exist in the wild, just about all bettas found in the aquarium trade come from commercial or hobbyist breeders.

Their long history of selective breeding has produced such a wide variety of coloration and fin styles that they have been called the “designer fish of the aquatic world.”

In the wild, the betta lifespan averages two to four years. If well kept, they can live up to nine years in an aquarium and learn to recognize their caregivers.

Bettas are exceptionally tolerant of low oxygen levels and poor water quality. They have a lung-like organ that allows them to take gulps of air from the surface.

This ability to live in low oxygen water makes them easy to keep. But this is offset by other factors which make them more complex to care for.

The great extent that the species has been bred to develop color and fin traits makes them more susceptible to illness, disease, and changes to their environment. Any of these factors can lead to bettas not eating.

If you ask yourself, “why is my betta fish not eating,” knowing the causes and solutions will help you keep those bettas alive.

How Long Can a Betta Fish Go Without Food

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While your betta fish not eating is bad news, the good news is that your fish will not starve immediately. It’s not uncommon for a betta fish to stop eating for a day or two, especially when you have just made some change to their environment.

Most betta fish can go for a week without eating, but they can live without food for as long as 14 days. However, when this happens, the fish will go into starvation mode and, in its weakened condition, can become subject to illness. Its chances of dying are greatly increased.

If you are a good keeper, you feed your betta fish at least once daily, so you will know if it stops eating. If this happens, watch your betta fish for a day or two. If your betta fish does not resume normal feeding, read the following section, identify what has changed, and make the needed corrections, so your fish remain healthy.

Why Is My Betta Fish Not Eating? (Top 6 Possible Reasons)

Betta fish stop eating for specific reasons, most of which are within your ability to correct. The more aware you are of how you care for your betta fish, the less likely they are to stop eating or become sick.

Here are the six most likely reasons that betta fish has stopped eating and the solutions you can put in place to correct them.

Changes in Diet

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The leading cause of betta fish not eating is a change of diet. Betta fish are carnivores and do best on diets that are heavy in protein. Many keepers feed their betta fish commercial betta flakes or pellets, and the fish do fine. But betta fish develop their own eating habits.

Other keepers feed their betta pellets and mix in treats such as brine shrimp, blood worms, and other meaty foods. Most keepers follow a twice-daily feeding schedule. All of these are best practices but can also lead to your betta not eating. Here is why.

Betta fish are individuals with preferences for different types of foods. These preferences can change. You can do everything right, and they will still stop eating. If they are eating pellets or flakes, freeze-dried or frozen foods and suddenly stop eating them, they may have become bored with their current menu.

If you just moved them to a frozen or freeze-dried food type or have been eating pellets and stop eating, it could be as simple as they do not like their current meal choice.


If you think your betta fish not eating is because of a change in diet or diet preference, try these ways to feed your betta.

  • Make sure you are feeding your betta fish pellets or flakes made specifically for bettas.
  • Move from pellets to flakes or flakes to pellets.
  • Offer a mix of commercial food and live, dead, or freeze-dried food.
  • Switch things up until you find a food choice they like.
  • If you are giving them too much food, cut back on their portions.

This is the most easily addressed solution. One of them should get your fish to eat. If you have rotated through all your food options, it’s time to look at other potential issues.

A Change In Their Environment

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One of the most stressful things you can do to a betta fish is to move it to a new aquarium. When you move a fish, it is not uncommon for it to stop eating for a few days as it adjusts to the new surroundings.

After a few days, as long as the other factors in the aquarium are within their tolerance levels, your betta should resume eating.

A common mistake new betta fish keepers make thinking you can keep them long-term in the small fishbowl or vase you may have received the fish in. Some try to keep their betta fish in similar small bowls that make it a design element for a desktop.

These cramped, empty fish bowls are like a prison for your new betta fish. They keep fish stressed, which makes them more prone to not eating and to getting ill. At a minimum, keep solitary bettas in two-gallon aquariums. This gives them room to move and feel like they are in a normal environment [2].


While betta fish do well in solitary aquariums, the ideal habitat is large enough for a solitary fish to move around and has a few plants anchored in the substrate for the betta to interact with.

  • Avoid frequent fish moves.
  • Try to keep your betta fish in an aquarium that has some variety to it.
  • Keep your betta fish in an aquarium that has enough space for it to move around.

In an aquarium move, expect your betta fish to be off its routine for a few days. It will usually go back to its normal behavior as it adjusts to its new space.

The Water Parameters Have Shifted

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Betta fish are very sensitive to changes in water temperature. If your fish is not eating and you have changed up its food, check the water temperature. Water that is too warm or too cold can quickly lead to fish not eating.

The damage can be far worse. Keeping betta fish in water colder than their ideal temperature range can weaken their immune system even in a short time.

Keeping them in water hotter than their temperature range boosts their metabolism to unhealthy levels, causing them to starve and weaken. Water too hot or too cold opens the door to disease and the possible death of your fish.

Betta fish can live in water from 70F to 80F and do best in 75F to 80F. This is not difficult to maintain when you live in warm climates but can be a problem if you air condition your house lower than 70F or the temperature drops below 70F at night.

If you are not paying attention to the water temperature in your betta fish tank, you could be slowly killing your fish!


One of the best things you can do to your betta aquarium is to have a thermometer in it so you can keep an eye on the water temperature. If it falls outside the ideal range for bettas:

  • Add a heat lamp to maintain water temperature.
  • If the temperature fluctuates in the aquarium or in the room the tank is kept in, add a timer to the heat source so you can maintain aquarium temperatures at 75F to 80F.
  • If moving fish from one aquarium to another, make sure both tanks have the same temperature to reduce the risk of stress and shock.

Water-Quality Changes

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Many people receive betta fish as gifts and think that their fish do not need much water care. This could not be further from the truth.

While betta fish may not be as sensitive to water quality as more delicate species, they are still sensitive to changes in water quality. If you have a betta fish not eating, the pH level might be outside their normal range. Similarly, additions of chemicals such as chlorine or ammonia can affect betta appetites.

There are many reasons why water quality can change. What you do not pay attention to could become big problems for your bettas.


If you think changes in water quality are causing your fish not to eat, try these solutions.

  • Use test strips to measure the pH of the water. Bettas do best in water with a pH of between 6.5 and 8.
  • Observe the water in the aquarium. If it is cloudy or fouled from over-feeding and fish waste, change the water. Be sure to add water at the right pH and temperature.
  • Only use water that you know is free from chlorine and other chemicals usually found in tap water. Let the water sit for a minimum of 24 hours before adding it to the aquarium.
  • Change out at least 10% of the aquarium water weekly.
  • Make sure the filtration system for the tank is maintained and clean.

If you keep your bettas with care and attention, many of these potential issues are eliminated, if not greatly reduced.

Check For Illness

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Any of the solutions we have listed so far can cause your betta fish not to eat. But if your betta fish has become ill, loss of appetite is just the first visible symptom that you may have greater issues in your aquarium.

Bettas are susceptible to many common fish illnesses such as Ich and many types of fin rot. Within a day or two of loss of appetite, you may begin to see other signs of illness.

These can manifest as:

  • Loss of color
  • Changes in body shape such as distended bellies
  • Erratic swimming
  • Fuzz or heavy slime

These can get into the aquarium from other means as well. Newly introduced tankmates can bring disease along with them.


At the first sign of illness, follow these steps as your situation dictates.

  • If your new betta is in a solitary aquarium, begin treatment for the disease; it manifests with a commercially-made medicine.
  • If your betta is in a community tank, isolate it and begin treatment.
  • Monitor the other tank mates. If they show signs of disease, remove them from the tank and treat them.
  • Thoroughly clean the tank and filters.
  • Replace the water with new water that is properly conditioned and at the right temperature.

If you catch the disease early enough, you can treat and save your bettas. If you do lose your fish, purchase new ones from breeders or sources that guarantee the health of the fish they sell.

You Have A New Fish

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There is a widely held belief that bettas will attack anything you put in their tank. Though bettas have been bred for aggression, in aquariums large enough, you can cohabitate bettas with other fish species that they will not fight with.

However, you have to be cautious about tankmates for female bettas and extremely selective about tankmates for the more aggressive male bettas. The wrong tankmates can put your bettas into stressful fight or flight modes. If your fish is not eating, this could be a reason.

Your bettas will be continually aggressive towards tankmates who are of a similar size, color or have similar types of fins. Conversely, your bettas will be harassed, bullied, and attacked by tankmates who are equally aggressive, territorial, or who are fin nippers.

Both of these situations can be the cause of your fish isn’t eating. And here’s the thing. If you do not correct these situations, they will lead to the maiming or death of your bettas. Here is what you can do if tankmate harassment is why your fish is not eating.


  • Add tankmates to the aquarium a week or two before adding the betta to allow the tankmates to establish their territories. This will reduce the level of turmoil in the tank as the betta makes its territory.
  • Use small schooling species such as tetras or danios as tank mates. They are too small to be threatening to a betta.
  • Avoid tankmate species that are known as fin nippers. They will harass bettas.
  • Avoid species that are brightly colored or have similar long, flowing fins. Bettas will be aggressive to these species.
  • Avoid aggressive, highly territorial species such as cichlids unless one one one or all fish to be maimed.

If the above fails, you can always isolate a betta into its own aquarium. As long as some aquascaping in the aquarium keep them occupied, they do fine as solitary fish.

Other Warning Signs

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If your betta fish is not eating, it is a sure sign something is up with your fish. But that is not the only warning sign. Sometimes your fish will eat just fine while other issues are beginning to appear. If you pay attention to your fish, you can catch any of these warning signs early enough to be prepared to take action to keep them from getting worse.

Sluggish Behavior

Bettas are not highly active fish except when feeding or displaying aggression. If they don’t chase their food or stop responding to other fish, this is a sign that something is wrong.

Loss of Color

It’s natural for any fish to become muted in color when moving them to a new aquarium. On the other hand, when fish that are established lose their color, it is a sign that they are not well or are not happy with their environment.

Distended or Bloated Bodies

Abrupt changes in body shape are something to watch for. Bettas can get what is called betta bloat, where their stomachs become distended.

This in itself is not bad news; fish can get a little constipated, and it can clear up in a few days. But bettas can also suffer from swim bladder disease and dropsy.

Swim bladder disease is just a generic term for bloating or slight body contortion that lasts for a few days. You really cannot do anything about this. Just do not feed your fish for a few days and see if it bounces back.

Dropsy is far more serious and usually fatal. The disease is indicated when the betta’s scales start to bristle out from their body. This is caused by internal organs swelling. There is little to do at this point except euthanize the fish.

If your female betta develops a swollen belly, she may be carrying eggs. The development of white markings on her belly can help confirm that diagnosis. If you have a pregnant female betta, consider putting a male in the tank with her so they can spawn. Be sure to return the male after she has laid eggs.

Erratic Swimming

If your betta begins to swim erratically, bloated or not, it can be a symptom of several different diseases.

By erratic swimming, we mean swimming in corkscrew patterns, swimming sideways, floating, and other abnormal motions. There is not much to do except isolate your fish in a clean, conditioned, and proper temperature aquarium. Watch them closely.

If your fish do not improve quickly, you can try a generic fish treatment or find a solution that supports the specific symptoms you are in your fish.

Visible Mold or Fungus

Compared to some diseases that bettas can catch, visible mold or fungus is almost a relief because it gives you something you can treat immediately.

Various mold, fungus, or slime patterns give a good indication of what you are dealing with. Isolating them and treating them with a medicine such as malachite green is the proper course of action.


Now you know that the reasons why your betta is not eating can be easy to correct or can take a lot of work. Here are the key take-aways you should have in mind if it happens to you:

  • First thing: If your betta stops eating, wait a day or two and observe.
  • Add some variety to their diet. Mix up pellets, flakes, and live or frozen foods.
  • Don’t keep your betta in the little container it came in.
  • Ensure you home your betta in a proper aquarium with correctly conditioned water at the ideal temperature range. Those are a pH of 6.5 to 8 and a temperature of 75F to 80F.
  • Make sure the aquarium has a good filtration system with gentle water return.
  • Keep the aquarium clean and change the water regularly.
  • Don’t let your betta get bored. Add plants, rocks, and structure to give your betta something to explore.
  • Bettas do OK in solitary tanks as long as they are not bored.
  • You can house them with tank mates that are small, schooling types.
  • If your bettas come down with illness or disease, isolate them immediately.

Beyond the novelty of their brilliant colors and beautiful fin varieties, bettas are unique fish that, when well cared for, will live for years and provide you with the joy of supporting a species that has been kept for more than a thousand years.

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