Betta Fish Not Eating? 10 Common Reasons Why

Is your Betta fish not eating? Most fish owners (and all pet owners in general) will probably go through this challenge at some point or another.

There are many reasons why you’re betta could be avoiding eating. Though not all of them are bad. I’ve had a couple of moments where I wasn’t sure why my betta didn’t want to eat their food. They would just stare at it as it fell to the bottom of the tank.

After a consultation with my vet, it turned out my betta was stressed because of its tank size. 

While I was able to solve this situation with the right betta fish tank size, some bettas might be dealing with other issues that can cause them not to eat. 

But don’t worry yet. 

We have a couple of reasons to help you figure out what’s wrong with your betta and what you can do to help them. 

Read on to find out some of the top reasons why your betta isn’t eating! 

10 Reasons Why Your Betta Fish Is Not Eating

The most important thing you should know about fish keeping is that sometimes you can’t be too quick to act. This may cause even more damage if you end up getting a solution to a non existent problem. 

1. Stress

If there is one thing about bettas, it’s that stress really affects their day to day lives. These fish are very sensitive to their environment. While bettas seem tough, a lot of external factors can affect their appetite, even for tasty treats. 

stressed betta fish

Some stressors include a small tank, lack of enough habitat features like caves and plants to keep them entertained, or unfriendly tank mates.

Poor water parameters can also stress out your betta and reduce their appetite for food. 


Eliminating these stress factors can help bring back your bettas appetite. If they don’t like their tank mates, you should find them friendlier companions to keep the peace. A stress free betta is a healthy betta. And a healthy betta loves to eat. 

2. You Have a New Betta

If you just took your new betta fish home, the change of scenery and environment might be why they’re not eating as much or at all. Bettas easily get stressed when moved to new locations with different water temperatures, lighting, or space in their tank.

Adjusting to a new environment is stressful for most animals, even a new betta fish. Sometimes it’s hard to determine how they will react. While some bettas can get aggressive, some will lay at the bottom of the tank and not eat. 


While it could take a couple of days for your betta to get used to their new habitat, there are ways you can help them feel more at home. 

Ensure you add plants, caves, and other hiding places to their tank. Though you should be careful not to crowd the tank so they have enough swimming space. The water temperature should also be appropriately warm for these tropical fish to prevent cold temperature shocks. 

Bettas love to swim so a large, spacious tank will help them ease into their new life with you. You should also give them time to adjust from the local fish store environment to your tank at home.

3. Illness

If you’ve been observing your Betta fish and you feel that stress isn’t what’s causing them not to eat then they might be sick. When bettas are unwell, the last thing on their mind is food. 

You’ll have to monitor their behavior and check their body to be sure. Sick betta fish will either have white spots on their body, unusual swimming patterns, or lack an appetite even for their favorite foods. 

Other symptoms of illnesses include rotting fins and sores on their bodies. 


To help your betta if they’re sick and you’re unable to identify what the issue/sickness is, it’s best to talk to a vet. They will appreciate any useful observations you made to help pinpoint the sickness your betta is suffering from at that moment, and can provide them with antibiotics if necessary.

Most fish illnesses are curable so don’t start panicking before you’re sure of the problem . While different illnesses need different types of treatment, there is one thing you can do that will help your betta fish. 

Change the aquarium water. 

If you change the water and your betta’s appetite returns, it could be the problem. Tank water quality can cause your betta to be sick and lose their appetite. 

4. Sudden Water Changes

How often do you change your betta tank’s water? Depending on the tank size, you should change the water at least once a week to keep it healthy enough for your fish. 

Changing the water is good, but you should be careful not to disrupt your bettas environment while doing it. If you change the water and replace it with very cold or hot water, your betta can go into temperature shock. 

Drastic changes in temperature can weaken your betta’s immune system and even lead to death. Temperature shock could be what’s making your betta fish not eat.


When changing the tank water, ensure you retain the water at the same temperature as before the change. Betta fish require their water temperatures to be warm at 78-82°F

You should also make sure that any water you add to the tank doesn’t have chemicals like chlorine.

5. Poor Water Quality

While some beneficial bacteria are in your betta’s tank, the water shouldn’t be dirty. Dirty tank water can be caused by excess waste or uneaten food at the bottom of the tank. Prolonged poor water quality in your betta’s tank leads to illnesses.

Poor water quality also causes excess waste build-up in the tank. Chemicals like ammonia and Nitrate are poisonous to bettas. Eventually your bettas immune system will be affected and they might stop eating.


One of the best ways to ensure that the water in the betta tank is OK is by adding a filter. Filters help clean the dirty water so you don’t have to spend hours scooping poop or leftover food from the bottom of the tank. Sponge filters are the best for betta fish tanks. 

If you want to prevent the ammonia levels from reaching a level that is harmful to your Betta fish you should get an aquarium test kit. These test kits will help you to keep track of the chemical levels in your fish tank. 

6. Overfeeding

Sometimes your betta doesn’t want to eat because they are full. How many times a day are you feeding your betta? Twice a day for an adult betta is generally enough. 

Bettas are small fish with even smaller stomachs so they don’t need a lot of food to be full. If you overfeed them, they will end up releasing excess fish waste into the tank water which is turned into ammonia. 

Excess ammonia in the tank causes ammonia poisoning that is lethal to these small creatures. Similar to humans, overfeeding can cause bloating in fish, and we know how uncomfortable that can be. 


To prevent overfeeding your betta fish you need to monitor them when they eat. Are they only eating two or three pellets during each meal? If so, your betta might be telling you that that amount is enough for them. 

You can cut back on the number of pellets or reduce their feeding times per day. It’s recommended to feed your betta two to four pellets at least twice a day. 

7. Your Betta Doesn’t Like Their Food

Bettas are picky with what they eat. Being omnivorous, they can eat both plants and meat. In their natural habitat, bettas survive on insect and insect larvae. Moving them to a completely different diet than the one they are used to at the pet store can make them stop eating. 

Ensure that the food you’re giving them is fresh. If you have an open tub of pellets that’s been laying there for a couple of months it’s probably time to get your betta some new fresh food. 


If they don’t like eating the pellets that you buy from the local pet store you can try adding some frozen or live food to their diet. Foods like raw shrimp, bloodworms, and brine shrimp might add the excitement they are looking for to their diet. Like humans, they might be more eager for their food if it isn’t the same pellets everyday. 

8. Your Betta Fish Is Confused

When you buy a betta fish from a breeder, they are likely on a very different diet than what you’re offering them now.

To spawn more bettas, most breeders will feed these carnivorous fish with a combo of frozen and live foods to help them grow stronger and faster. While this food combination is great for your betta fish, its not practical for most fish owners. 

Foods like betta pellets and flakes might be new to your pet fish. Like everything else in their new aquarium, they need to adjust to the new foods and eating habits. And they’re probably slightly confused that those pellets are now part of their balanced diet. 


If this is the reason you’re betta fish isn’t eating, you just have to give it some time. Eventually they will realize that those objects you’re dropping into the water are food and start eating when they become hungry enough.

You should also have some of their old foods around so they don’t starve before adjusting to their new diet. 

9. Their food is frozen

It’s no surprise that this tropical fish doesn’t like anything cold. That includes their food. If you’re dropping frozen or freeze dried food into the tank, your betta fish will likely just ignore it. 

Leftover food can increase the ammonia levels in the tank, which is poisonous to bettas. Ammonia poisoning could also be the reason your betta is not eating anything.

The frozen food needs to soften up a little so your betta can easily eat and digest it. Some frozen fish food will expand when they absorb water so your betta might have a hard time digesting it. It may lead to constipation or worse: swim bladder disease. 

You should check the fish’s belly to be sure. If it’s round and your betta isn’t eating, they might be constipated. If they’ve suffered from swim bladder disease because of eating frozen foods, they might be wary to try it again. 


If you’re freezing you’re bettas food, ensure it is completely defrosted before feeding it to your betta in their tank. You can place some frozen food in a cup filled with the tank water until it defrosts before dropping it in the tank. 

10. They’re Scared of Their Reflection

While this one might sound like a weird reason, bettas are very territorial fish. You’ll see this trait with bettas who have to share their tanks with other fish. Sometimes, your betta fish might see their reflection on the tank and think it’s another betta coming to take their place. This causes them to gear up for a fight by flaring their gills.

Before they start fighting, bettas flare their gills to make them look bigger. Continuous gill flaring is exhausting for bettas and causes stress because these siamese fighting fish are preparing for a showdown.

Your betta fish could be flaring because of their reflection, the new tank, or to defend their territory.

When a betta is gearing up for a fight, there is no time to think of what to eat. 


If your betta doesn’t have an appetite because they’re flaring at their reflection, you need to reassure them that they have no competition. 

You can adjust the aquarium lighting so they don’t see their reflection in the tank anymore. Adding some plants can also block their view to prevent them from flaring at their reflection. 

Wrapping Up

At this point, you hopefully should have an idea as to why your betta fish isn’t eating. Are they stressed? Is the water temperature causing the problem, or do they not like the food you’re offering?  

While some reasons require a simple solution like changing their diet, you should also give your betta time to adjust to the changes you are making to their home. Observe their behaviour after changing the water or changing their diet to determine if that was the real problem. 

With constant observation and maybe a walk with a vet you can better understand why your betta fish won’t eat. 

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