Why is my betta fish lethargic and not eating?

In this post, we will understand the relationship between the betta fish not eating and being lethargic. We will also outline how to keep your betta fish healthy.

Why is my betta fish lethargic and not eating?

A very concerning fact is when your betta fish appears to be sluggish and has stopped eating. It is not customary for betta fish to spend long amounts of time on the bottom of the tank or in an open area where they feel vulnerable, even if bettas do sleep, snooze, and relax.

While betta fish are known for their fondness for hiding under-display pieces, they should be active and responsive when they are in good condition. When they hear or see you coming into a room, betta fish often swim to the front of the tank to greet you. Algae eaters can be good company for betta fish, but I wouldn’t recommend keeping bettas in an aquarium with other bettas because betta fish tend to be a bit aggressive with each other.

Betta fish and water conditions

Water quality is the most prevalent cause of bettas becoming sluggish. The water in your aquarium should be warm enough and clear of any harsh chemicals that might make your betta sick, so follow a guide while setting it up. Also, keep in mind that a betta fish may become sleepy after a complete water change if the tank has not been properly cycled or reintroduced with good microorganisms.

Bettas’ energy is dependent on the temperature surrounding them. If you’re keeping your betta in a tank that isn’t warm enough then it’s going to result in tiredness and reduced metabolism. In order to save energy, your betta will eat less food if its metabolism slows down.

Smaller water changes are all that are needed to keep ammonia levels in check, and this may easily be prevented by doing so often. It’s also a good idea to ensure that the tank you choose for your betta fish is large enough to accommodate the fish.

Your betta may be sick if he has recently stopped blowing bubbles from the top of his tank. It’s important to note that not all sick bettas stop blowing bubbles, thus this isn’t universally true. Some bettas never blow bubbles in their tanks, while others do so even when they are unwell, but many bettas blow bubbles to demonstrate that they are healthy and happy (for breeding.) For the most part, you can tell if your betta fish is active by his bubble production, but you can also use a camera to monitor his activity levels for more clarity.

Betta fish and constipation

A constipated Betta may not be eating because it has been fed too much. Even though constipation can lead to a betta fish’s early death, it is quite straightforward to treat your fish with a little bit of a pea. Peas are a great source of fiber and should encourage the fish to use the bathroom more frequently.

What may cause a new betta to be sluggish or unwilling to eat?

Normally, a new fish stop eating in a few days, they are adapting to a new environment. However, after a few days, if a freshly acquired fish isn’t eating or appears sluggish, there are things to look into.

The water quality can degrade quickly when fish are kept in tiny containers at retail establishments. We tend to believe that rushing the fish to clean water is the best course of action.

When it comes to fish, rapid changes may be dangerous and even fatal if they are too large.

You may want to conduct a pH test on the water they came in if you can. If the new fish’s tank water has a pH difference of one full point or more from the water in the cup, please allow the fish to acclimate for at least a day before adding it to the tank. A whole point of pH ranges from 5-6 (or 8-7) to 8-7, not the minor points between.

Remove a little amount of water from the container and replace it with a similar volume of freshly conditioned new water. Repeat the procedure many times a day.

A day or two later, when the fish is introduced to the new tank water, he won’t be as frightened and will be able to adapt more readily.

What things you should pay attention to in a betta fish tank?

Ammonia, nitrite, and nitrate may all be found in the water, therefore this is the first thing to look for. Always keep a supply of water testing equipment on hand. There is no other method to learn what tests can tell us, thus they are critical.

Having a tank that is too small is the second most common issue encountered.

Anything less than 3 liters is too little for the fish. If you’re going to keep fish, don’t keep them in a container that’s less than one gallon. At least three liters of water are required for a vase to be suitable. Betta fish don’t live in little puddles, despite what the pet retailer told you.

Small containers don’t work for them.

Partial water changes are not enough if they are not performed at least once each week.

Every week, it is recommended at least 40% of the tank’s volume change.

If you want to keep Bettas healthy, you need at least 5-gallons (20 liters) of water.

To ensure that your fish have a long and healthy life, you should provide them with greater room to roam.

Another thing to pay attention to is the water temperature. The temperature of their water must be maintained at 78 to 82 F degrees at all times. You need a heater to check if the temperature keeps in place and does not get too cold or too hot. It’s common for fish that have been cooled to not eat or move much.

Furthermore,  a young fish’s first few weeks in a new home are often plagued by a lack of energy and hunger.

My fish is sick. What should I do?

When your fish seem to be ill, the best thing you can do is do a half-tank water change.

 Daily or bi-weekly adjustments aren’t excessive in the case of fin rot, which is quite prevalent. Before adding additional water, make sure it’s at the right temperature and has been dechlorinated.

Betta fish dietary needs and recommendations

Food that sinks to the bottom of the bowl will not be eaten by all Bettas. The form of their jaws may be seen. Fish that feed on insects and other surface-feeding organisms generally have their mouths turned upward.

As the meal dips below the surface, some of these fish will not follow along with it. You should expect them to eat a pellet and then vomit it out again. It can be a method of progressively reducing the size of the food, and in most cases, it will keep going until it is gone.

Using smaller pellets, such as 1 mm in diameter when dried, can help with this. Dry food should be pre-soaked in a small amount of tank water to ensure that it is well-moisturized before using it. Moist food is considerably more readily consumed by fish. As a result, the stomach won’t grow excessively after eating dry food.

Include in the betta fish diet live food. Live food may be found in the fish’s tank at any time, and they have no issue following it around or lifting it from the bottom. Aside from its nutritional benefits, live food is a fantastic way to improve the habitat for these animals.

As well as getting the excitement and activity they need, they may indulge in their innate hunting impulses.

They would spend much of their time looking for food if they were to live in the wild. When it comes to food, there are several healthy options to select from. Adult brine shrimp may be excellent, especially if they are fed a high-quality diet before they are harvested. Daphnia and mosquito larvae are excellent sources of protein. Both of these will be able to survive in the tank till consumed. Alternatively, you can wait until the mosquito pupates before disposing of the pupa.

Amphipods (gammarus), sometimes known as scuds, are another option.

Fish like to eat fruit bugs, known as Drosophila melanogaster

Additionally, because bloodworms are high in fat, they should only be fed to pets every week.

Bettas can also benefit from additional enrichment in their habitat.

It is recommended to include some live plants in his or her aquarium. There are a variety of ways to decorate your home, as well. Things that the fish can swim through or around are an important part of this strategy. Nitrates are used by plants as food and thus contribute significantly to water quality. With live plants, nitrates are seldom a concern in the water supply.

Plants made of silk or plastic will work, but live plants are preferable because they are more like the fish’s natural home. The Betta’s fins can be damaged by sharp, abrasive, or rough edges. Check every surface and edge for anything that can grab a fin before you go in the water.


In this post, we understood the relationship between the betta fish not eating and being lethargic. We also outlined how to keep your betta fish healthy.

if you have any questions, let us know below in the comments!

Frequently Asked Questions (FAQs): Why is my betta fish lethargic and not eating?

Why is my betta fish lack energy?

It is fairly typical for betta tanks without heaters to experience temperature shock, which can be extremely dangerous. If you’re not familiar with temperature shock, it’s when the water temperature lowers or rises too quickly. It’s more probable that your betta will get sluggish and lie on the bottom of the tank if the water becomes too chilly.

Why does my betta fish seem sluggish?

The water temperature is too cold. Lower temperatures cause a reduction in your fish’s metabolic rate. In addition, the rate at which oxygen is absorbed is slower. When all of these things happen at once, your fish will become extremely weak and sluggish. Your fish may grow ill if you don’t raise the temperature.

When a betta fish is dying, what does it look like?

A betta fish’s body may show evidence of discoloration, such as white or brown blotches, when it is close to death. Severe sickness might be indicated by unusual swimming motions or a shortening or eating away of the fins.

What is wrong with my betta fish?

If the temperature in the tank is too high, you may notice a betta fish not eating. Because Bettas are cold-blooded, a large portion of their energy comes from the surrounding environment. Lethargy and a slowed metabolism are likely outcomes if your betta is housed in a tank that is too cold.