Betta Fish Laying at the Bottom of Its Tank: 13 Reasons & Solutions

If you’ve noticed your betta lying at the bottom of the tank, you may be concerned about its health. 

The good news is it’s common for a healthy betta to rest or sleep on the bottom of the tank. But sometimes, this behavior indicates a problem with your betta’s health or environment. 

Common reasons for this behavior include health issues, such as swim bladder disease, lack of proper nutrition, and a too-small aquarium size.

Luckily, most of these issues are fixable. 

#1 Poor Water Quality

Poor water conditions are a common reason betta fish lay at the tank’s bottom.

Water quality declines when levels of ammonia and other toxins rise. This happens when fish waste and leftover food are allowed to sit in the tank for long periods.

Betta fish may become stressed, lethargic, and more prone to various diseases as a result. Also, ammonia buildup leads to ammonia poisoning if left untreated. 

The Fix 

There are a few ways to prevent or treat poor water conditions in your betta fish tank:

• Install an aquarium filter
• Test the water for various substances, including ammonia
• Perform frequent water changes of 20% to 25% 
• Add water conditioner to the aquarium 

#2 Improper Diet or Overfeeding

Many new betta keepers make the mistake of overfeeding their fish. This is a problem since betta fish are already prone to obesity and digestive issues. 

Overfeeding often results in the betta becoming constipated, bloated, or obese. These conditions make it prone to lying on the floor of the tank. 

An improper diet may also encourage this behavior. Betta fish need a balanced, protein-rich diet to thrive.

Undernourished bettas are more likely to become sick or feel stressed. 

The Fix

To avoid overfeeding your betta: 

• Avoid buying low-quality food for your betta
• Follow the recommended feeding instructions on the packaging of your preferred betta food 
• Only feed your betta a couple of times a day 
• Skip feedings as necessary if your betta appears bloated or lethargic 
• Remove any uneaten food from the tank within a couple of minutes of feeding

To ensure your betta has a proper diet: 

• Buy commercial fish food specifically formulated for bettas
• Feed your betta various types of food (live, frozen, freeze-dried, pellets, flakes)

#3 Tank Size

Betta fish require a minimum tank size of at least 2.5 gallons, but we always recommend at least a 5-gallon tank. 

In their natural habitats, bettas have ample space to swim and roam by themselves. They’re also aggressive and territorial fish, meaning small spaces can make them feel stressed. 

Stressed betta fish are prone to behaviors such as flashing and laying at the bottom of the fish tank. 

The Fix 

If your betta fish appears unhappy with its current tank, consider getting a larger tank. 

As mentioned, we recommend a minimum tank size of 5 gallons for a single betta. If you plan on housing a sorority or giving your betta tank mates, a size of 10 to 20 gallons may be better.

Another remedy is to consider whether your current fish tank is just overcrowded. If there are too many plants, decorations, or other fish, consider moving some of the excess to another tank.  

#4 Temperature

Bettas thrive in specific water temperatures between 78-80° degrees Fahrenheit (25.5-27° C). 

If the water temperature drops below or exceeds this range too quickly, your fish may become ill or stressed.

Bettas express this through behaviors such as flashing, lethargy, and laying at the bottom of the tank. 

The Fix

There are a couple of ways to ensure the aquarium water always remains within optimal parameters.

The first is to install a tank water heater.

This is a device used to keep the water within a certain temperature range. Having a water heater means you won’t have to worry about constantly monitoring or adjusting the water temperature.

The second is to buy a water thermometer.

Even with a water heater, it’s a good idea to check the water temperature every so often. This way, you know if there’s a sudden drop or increase and can take action in a timely manner. 

#5 Illness, Disease, or Infection

Unfortunately, betta fish are prone to a variety of diseases and infections. Some of these health issues result in bettas laying at the bottom of the tank. 

A few of the most common betta fish diseases include the following: 

• Swim bladder disease
• Dropsy 
• Constipation
• Fin and tail rot
• Intestinal parasites

The Fix

The best way to avoid this problem is to prevent your betta from becoming ill in the first place. 

Here are some tips to keep in mind: 

• Maintain optimal water parameters. Bettas are tropical fish, meaning they need warm water temperatures. Keep the temperature between 78-80° degrees Fahrenheit (25.5-27° C) for the best results. Also, install a water filter to prevent toxins — such as ammonia — from building up in the tank. 
• Feed your betta a balanced diet. Bettas need a balanced, protein-rich diet to thrive. We recommend feeding your betta pellets or flakes specifically formulated for betta fish, in addition to occasional live or frozen foods. Be careful to avoid overfeeding! 
• Keep its stress and aggression levels low. This means providing plenty of hiding spots, sufficient lighting, and suitable tank mates (if any). 
• Quarantine any new fish or plants. Other fish and plants may also carry diseases or parasites which might infect your betta. Before putting a new fish or plant in the tank, quarantine it in a separate tank for several days. 

If your betta has already fallen ill, we recommend having a vet examine it. They will provide a proper diagnosis and suggest the most suitable treatments. 

There are also plenty of over-the-counter betta fish medications both online and in pet stores. Research any medication before buying it, and ensure you follow the directions on the packaging. 

#6 Stress

A crucial aspect of betta fish care is keeping the betta’s stress levels low. This is because overly stressed bettas tend to engage in unhealthy behaviors: 

• Flashing 
• Excessive hiding
• Fighting with other fish 
• Laying on the bottom of the tank 

Stress also opens up your betta to numerous diseases and infections. 

The Fix

There are a few different reasons why betta fish tend to feel stressed: 

1. Lack of hiding places. Reduce your betta’s stress levels by providing plenty of hiding spots in the tank. Consider placing some driftwood in the tank, or buy tank decorations with hidey-holes. 
2. Improper water parameters. While bettas are hardy fish, they still need specific water parameters to thrive. This includes things such as temperature, pH, and water hardness. 
3. Poor water conditions. Your betta will feel stressed if the water conditions are poor. Avoid this issue by installing a tank filter and regularly checking toxin levels. 
4. Strong currents. Bettas are used to the sluggish waters of Southeast Asia and surrounding areas. This means they prefer this slow water movement while in captivity, too. Tanks with strong currents may stress out your betta. We recommend using a low-flow filter in your tank, which will produce minimal water current. 
5. Too much or too little lighting. Fish tank lights are a good addition to most aquariums. But be careful to only provide the level of lighting your betta needs. Giving it too much or too little light may elevate its stress levels. 
6. Living with aggressive fish. Since bettas are rather territorial and aggressive, they don’t do well with other aggressive fish. If your betta feels threatened by an aggressive tank mate, it will become stressed and agitated. Only house your betta with smaller, more peaceful species, such as tetras, corydoras, and snails.

#7 Lack of Oxygen

Bettas have an organ called the labyrinth organ, which makes it necessary for them to have oxygen access.

They often go to the water surface for gas exchange, but there should be trace amounts of oxygen available in the water itself. 

In most cases, a simple tank filter will provide ample aeration for your betta fish tank. But sometimes, it becomes necessary to increase the oxygen supply even more.

This might be true, for example, if your betta is ill and struggling to swim to the surface. 

The Fix

Two common (and easy) ways to increase oxygen levels include adding aquarium plants and getting a bubbler/air pump or air stones. 

Plants draw CO2 from the water and release oxygen. There are numerous types of aquarium plants to choose from. Popular ones include anacharis, anubias, Java sword, and Amazon Frogbit. 

A bubbler or air pump will add oxygen to the water by increasing water movement. This often results in small bubbles being produced, as well. These devices are relatively affordable and can help your betta get the oxygen it needs while sick. 

#8 Poor Water Circulation

Betta fish prefer slow-moving water with a gentle current. If the water circulation in your tank is too strong or not strong enough, it may make your betta lethargic and stressed. 

The Fix

Installing a low-flow tank filter is the best way to maintain ideal water circulation.

Pushing the water around the tank will prevent it from becoming stagnant. Filters with a low-flow design do this without creating strong currents. These currents may stress out your betta. 

Another benefit of a betta tank filter is in how it cleans the water. 

#9 Tank Decorations

While having tank decorations in your aquarium is a good idea, be careful about which ones you choose.

Some tank decorations have sharp edges or abrasive surfaces, which can damage your betta’s fins. This will make swimming uncomfortable, and your betta may lie on the tank’s bottom.

Also, tank decorations made with toxic paints or materials can make your fish sick. Toxins can leech into the water, decreasing the overall water quality. 

The Fix

When shopping for tank decorations, avoid those made from plastic and those with toxic paint or parts. Better material options include ceramic and silk, for example. 

We also recommend reading online reviews for any tank decorations you want to buy. This can give you a better idea of how well the item worked in other people’s betta aquariums. 

#10 Water Chemistry

As with temperature, betta fish need specific water chemistry to thrive. 

Bettas do best in water with a pH of 6.5 to 7.5, though a little variation is usually okay. 

If the pH becomes too high or too low, this can make your betta feel stressed or even fall ill. 

The Fix

Buying a pH test kit is the best way to ensure the water’s pH level is within optimal parameters.

This will allow you to regularly check the pH level and take timely action if needed. 

#11 No Tank Mates (or the Wrong Ones)

Usually, betta keepers will keep a male betta by itself or with peaceful community fish. While most bettas thrive in solitary environments, some do prefer the company of other aquatic creatures. 

If your betta feels lonely, it might become depressed or anxious. This could cause it to lay on the bottom of the tank. 

Another common issue is bettas living with non-compatible tank mates. A male betta should not live with another male betta or with other aggressive species.

Larger and more aggressive species might threaten or even attack your betta. This will lead to bodily injuries or even death, and it will cause your betta undue stress. 

The Fix

In most cases, it’s best to house a single male betta by itself. Some fish keepers enjoy keeping several female betta fish together in a sorority, which is also fine.

If your male betta appears to be lonely, consider adding some suitable tank mates. There are several great options to consider, including the following:

• Tetras
• Corydoras
• Snails
• Shrimp
• Guppies

When adding tank mates, ensure you quarantine them first.

Also, closely watch their and your betta’s behavior toward each other for the first few days. If you notice signs of aggression, consider getting a larger tank or housing your betta by itself again. 

#12 Old Age

In some cases, laying at the bottom of the tank is just normal betta fish behavior. This is especially true if your betta is on the older side. 

As bettas age, they have less energy and become less active. This may result in your betta spending more time laying at the bottom of the tank.

The Fix

Since resting more is natural as bettas age, there’s no real “fix” here. 

If you’re concerned about your older betta laying on the tank floor, consider buying it a betta hammock. This is a decoration or plant leaf close to the water surface for your betta to lay on instead. 

#13 Sleep or Rest

It’s also normal for your younger bettas to sometimes sleep or rest at the bottom of the tank. This behavior doesn’t always mean something’s wrong. 

Betta fish enjoy resting or sleeping in various parts of the tank, from the substrate to a high-up plant leaf. 

The Fix

Since bettas naturally tend to rest or sleep on the tank floor, there’s no real “fix” here. 

Buying a betta hammock or putting plenty of plants in your tank might encourage your betta to sleep elsewhere if it bothers you. 

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