Why is My Betta Fish Not Eating?

Why is My Betta Fish Not Eating?

Like every other living organism, betta fish need to eat in order to survive. However, sometimes your little buddy may refuse to eat, even though you may not see anything wrong with them externally. Now, the big question comes “why is my betta fish not eating?”

To answer the big question, your betta fish may not be eating, due to stress, incorrect water parameters, diseases, change in environment, and several other reasons. Some of these are very easy to correct while others are more difficult to fix. Being able to determine why your fish isn’t eating is the first step in fixing the problem.

In this article, we will go in details to point out the reasons why your betta fish may stop eating. Thus,  covering the following subheadings:

New Betta

New fish are stressed when they first come home due to the move. You can lessen this stress by drip acclimating your fish. Drip acclimation is simply dripping aquarium water into their cup at 2-4 drops per second and removing half the water from the cup once it gets full. Keep a constant drip on the cup, and after removing half the water twice, your betta is ready.

However, even with careful acclimation, your fish may be stressed and intimated by its new surroundings. This stress can leave the fish open to disease, but in the meantime, it may simply avoid eating.

When an animal feels that they are in danger, they will refuse to eat. This is because they let their guard down while eating and can not swim away as quickly once they’ve had a full meal. It is not unusual to get a new fish that refuses to eat, but most bettas are eager and willing as soon as you get them.

If your fish still does not eat 3-5 days after you buy it, there is probably an underlying issue with the betta. In the meantime, you can try feeding live food like California blackworms, daphnia, scuds, and bloodworms. You can also increase the number of hiding spots in the tank to try and make it feel more secure.


I’m sure you can remember a time in which you were very sick and didn’t feel like eating. The same goes for fish. If they are very sick, they will not want to eat. It is very difficult to feed a fish that is refusing to eat due to disease and you must first treat the disease.

Once a fish becomes so sick that it refuses to eat, the outcome is generally not good. This does not mean your fish is doomed, but you should be prepared for the worst. Fish can recover from this, but it is difficult since they are not bringing proper nutrients and energy into their bodies.

We have several articles that cover common betta diseases, how to identify them, and how to treat them, such as our “Betta Fish Care for Beginners”, “How to Treat a Sick Betta Fish”, and “Why is My Betta Fish Turning White” articles.


Constipation is a common problem with betta fish and easily treatable. It is usually caused by a fish being fed the wrong amount or type of food. Betta fish need to eat food meant for carnivores and cannot handle plant-based food. In addition, they should only eat an amount of food the size of their eye 2-3 times a day.

If your betta has an abnormally swollen belly, it is probably constipated. To treat it, you must simply fast your betta for three days then feed either part of a deshelled, blanched pea or some frozen daphnia. Both of these foods act as laxatives for bettas.

Swim Bladder Disorder

The swim bladder is an organ that controls a fish’s position in the water column. They let air out of this organ to go down and let air in to go up. However, this organ can be damaged or become infected, which will lead to swim bladder disorder.

Fish with swim bladder disorder have a hard time maintaining their position in the water column. They are normally either stuck at the bottom of the tank or at the top. It will seem like their back half is either constantly dragging them up to the top or to the bottom, depending on the type of the disorder.

Constipation can cause this disorder, so if you believe this to be the cause, simply try and treat constipation. If you see no signs of constipation and your water parameters are perfect, it is possible that your fish may have a bacterial infection, so you can try and use an antibacterial medication such as Erythromycin.

Swim bladder disorder can make it extremely difficult for a betta to maneuver and get to its food. If it is unable to swim properly, it may be unable to get to its food and eat it. Observe your betta carefully to see if it is unwilling to eat or if it is simply unable to reach its food.

Type of Food

As previously mentioned, bettas cannot eat plant-based food or food with many fillers. Bettas do have personal preferences when it comes to food, so if yours refuses to eat, has no symptoms of illness, and you’ve had it for some time, try switching up its food.

Bug Bites is a food brand that is based on insects. In the wild, insects make up the vast majority of a betta’s diet. Most commercial fish foods are based on fish meal, which is great protein for a betta, but is not what they would eat in the wild.

If switching to an insect-based food does not work, try switching to live food for a short period. Depending on what is available in your area, you may have to order some food online. If you are limited to chain stores, the only live food you will be able to find will likely be flightless fruit flies. These are easy to culture, but not all bettas are interested, and some may escape the aquarium.

If you have a local specialty fish store, you may be able to get California blackworms, daphnia, scuds, tubifex worms, and other small crustaceans. Bettas absolutely love all these foods, most of which are easy to culture, and are also available online if you cannot find them in stores.

Water Quality

Just like a serious disease, if your water quality is very poor, your betta will feel so bad that it will refuse to eat. If your tank is not fully cycled or went through a mini cycle, some ammonia and nitrite will be present.

Ammonia burns fish on the outside and often leaves large black burns. In addition, it causes severe damage to the gills, which can shorten the lifespan. Nitrite binds to hemoglobin in the blood and prevents it from carrying oxygen, which suffocates the fish. If you are being constantly burned or are suffocating, food is the last thing on your mind.

You must test your water, and if you find any trace amounts of ammonia or nitrite, you must do large water changes to remove all of it. Any amount of ammonia or nitrite is toxic to fish.

On the other hand, if you have not been keeping up with your weekly water changes, your nitrates will be very high, which can make your fish feel icky. If your nitrates are above 20ppm, your fish will feel the effects, and if they are over 80ppm, you cannot do normal water changes.

If your nitrates are extremely high, you must take water changes slowly, otherwise, your betta can go into nitrate shock. For nitrates between 80 and 120ppm, do three to five 10% water changes daily until they drop below this number.

For nitrates over 120ppm, do three to five 5% water changes daily until they drop to 120ppm, then do 10% until they drop below 80ppm. At this point, you can do larger water change up to 50%.

Old Age

Once your betta fish begins to get older, its metabolism will slow down. This will cause it to eat less but shouldn’t cause it to stop eating altogether. Because the metabolism is slower, your betta will not be able to digest as much food as it once did, and it will not need as much energy.

If your betta is simply getting old, there isn’t anything you can do for it. Continue weekly tank maintenance and to feed it a good variety of food. Provide some extra resting places all over the tank, especially near the top.

Metabolism/ Temperature

Just like old age, if your betta’s temperature is too low, its metabolism will drop significantly. This will lead to it eating less, but not stopping altogether, unless the temperature is excessively low.

Betta needs a heater because its temperature must be between 78- and 80-degrees Fahrenheit to have the best metabolism. Betta fish are cold blooded, meaning their internal body temperature is dependent on the surrounding temperature.

If the tank’s temperature is above or at 70 but below 78, your betta will be very lethargic and unwilling to eat most of the time. If the temperature is below 70, your betta may die from its body temperature being too low and will likely refuse to eat at all.

In conclusion, your betta fish may stop eating for a variety of reasons. All these possibilities have a fix, and most of them are very simple to fix. Eating is an essential part of keeping your fish healthy and alive, so take note if your fish is suddenly refusing to eat.

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