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Home > Fish > Why Is My Betta Fish Not Moving? 12 Vet-Approved Reasons

Why Is My Betta Fish Not Moving? 12 Vet-Approved Reasons

Delta Tail Betta Fish

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Dr. Lauren Demos

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Bettas or Siamese fighting fish are lively and usually active fish that are popular additions to nano aquariums. It is concerning when a betta fish becomes inactive and doesn’t move much, and it is usually an indication that something is wrong with them. Although it is common for long-finned bettas to be much slower swimmers that rest frequently, it is not normal for them to not move much at all.

Determining the reason behind your betta’s inactivity can help you find a suitable solution and encourage your betta fish to become more active again.

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The 12 Reasons for an Inactive Betta Fish

Below are the 12 most likely reasons for your betta fish to not move much or at all.

1. Stress

Betta fish can get stressed for a variety of reasons, such as poor water quality, an illness, or the wrong environment. Betta fish need to be fed a quality diet and be kept in the right living conditions and water quality. Stress is not good for bettas and may even cause them to be lethargic or ill.

2. Sleeping/Resting

When bettas are resting or sleeping, they usually don’t move much. They will find a comfy spot to rest and stay there for most of the night. A resting betta fish will not move much during the night, and they won’t have any visible signs of disease or stress. Their fins won’t be clamped, and their activeness will return in the morning when their aquarium lights are turned on again.

betta fish in aquarium
Image credit: Kosit Pajuthai, Shutterstock

3. Illness

Various illnesses can cause your betta fish to become lethargic. When a betta is feeling sick, they won’t be very active and spend more time hiding or laying at the bottom of the aquarium. Depending on the type and severity of their illness, most betta fish will become active again once they receive appropriate treatment.

4. Poor Water Quality

Betta fish require good water quality in their aquarium to stay active and happy. High levels of ammonia and nitrite in the water are dangerous for bettas and can make them feel stressed. They will spend more time at the bottom of the tank and appear lethargic. In cases where the water quality is very bad, your betta will become listless and show signs of ammonia or nitrite poisoning.

All of their waste products and uneaten food build up in their aquarium, which needs to be processed by a filter. Water changes are also important as they help to dilute the waste in the water.

Allowing their aquarium to undergo the nitrogen cycle before adding them in allows enough beneficial bacteria to form to keep the ammonia and nitrite under control. Once the aquarium has been cycled properly, the biological filtration system will convert ammonia and nitrite to the less toxic form, known as nitrate.

You can determine the exact readings of ammonia, nitrite, and nitrate in the water by using a liquid testing kit. Both ammonia and nitrite should be at 0 ppm, and nitrate below 15 ppm.

betta fish in a dirty aquarium
Image Credit: Edwinzone, Shutterstock

5. Incorrect Water Temperature

Bettas are tropical fish that can become inactive at temperatures out of their ideal range. Temperatures between 72 to 82 (22°C to 27°C) degrees Fahrenheit are ideal for betta fish, although a temperature around 78 degrees Fahrenheit (25°C) is recommended. If your betta is kept in cold water temperatures, they will not move much. Their metabolism functions best at warmer temperatures, and the wrong temperature affects their appetite, movement, and even respiration.

You ideally want to keep their water temperature stable using an aquarium heater. The water temperature shouldn’t fluctuate much throughout the day and can be monitored by an aquarium thermometer.

6. The Wrong Foods

A healthy and balanced diet is essential for a betta’s overall health and well-being. If your betta is fed the wrong types of food, it may affect their activity levels. This is also possible if you are under or overfeeding your betta fish. Bettas are naturally carnivores and their diet in captivity should contain foods that they naturally eat in the wild.

You should ideally be feeding your betta fish a high-quality pellet or flake food formulated for bettas. Their food should contain nutritious ingredients and be low in fillers and artificial additives. Offering them live or frozen foods like daphnia, bloodworms, and brine shrimp up to five times a week ensures that they are receiving the right nutrients they need to stay healthy.

Bettas should be eating once or twice a day, and only enough food that they can eat within a few minutes.

Half moon Betta fish
Image Credit: at.rma, Shutterstock

7. Wrong pH Level

Betta fish require a slightly neutral pH range between 6.5 to 8.0. This is the pH range that they naturally experience in their wild habitat which consists of rice paddies, ponds, streams, and marshes.

The pH level of the water can play a role in your betta’s overall health. So, when it is out of their ideal range, your betta fish may experience pH-related issues such as inactivity. The pH level in the water does seem to influence a fish’s physiological processes like respiration and general activity levels. A very low pH may also burn your betta’s sensitive skin and make them feel sick, resulting in sluggish behavior and visible burns or lesions.

However, the pH level in an aquarium isn’t visible to the naked eye. If you want to find out whether the pH could be a problem in your betta’s aquarium, you will need to use an aquarium pH test. You want the pH to be stable in their aquarium and not fluctuate. An unstable pH level can be stressful for betta fish. If the test does give a reading that is out of a betta’s ideal pH range, you need to be cautious about raising or lowering the pH. Doing it too fast can put your betta fish in shock, which is dangerous.

8. Lighting Issues

Betta fish need a natural day and night cycle like they would experience in the wild. You should never leave your betta fish in complete darkness or leave their aquarium light on both day and night. This could be the reason your betta fish isn’t moving much since their sleeping patterns and behavior are influenced by lighting. Messing with the amount of light and darkness they receive may even affect their natural circadian rhythm.

Furthermore, very bright lighting isn’t recommended for betta fish. The bright lighting can be stressful for them, and they seem to prefer a low to moderately bright light instead. You can leave the aquarium light on for 6 to 10 hours a day and switch it off at night. Betta fish need a period of darkness at night to rest.

betta fish in aquarium with nature light
Image Credit: MANU PARADY, Shutterstock

9. Incompatible Tankmates

Betta fish in general are solitary fish, especially the males. Male bettas should never be housed together once they are mature since they will fight until severe injury or even death. Although female bettas can sometimes be kept together in what is known as “sororities”, this should only be done by experienced fish keepers.

Keeping them with the wrong tank mates can be stressful for bettas. They may prefer to hide away to avoid being injured by aggressive tank mates.

10. Old Age

Betta fish generally slow down as they age. The older a betta fish is, the less active they might be. Bettas generally have a lifespan of around 3 to 5 years, and slow down at around 2.5 years of age.

betta fish coming out from a pot in aquarium
Image Credit: Kosit Pajuthai, Shutterstock

11. Wrong Aquarium Size

Improper living conditions don’t provide your betta with the right environment to keep them healthy and active, so this could be why your betta fish is preferring to stay in one spot.

Betta fish require a spacious fish tank ideally over 5 gallons in size, with a filter and heater. They do not belong in small unfiltered bowls or vases, even though they are small fish. Making changes to their environment by upgrading them to a filtered and heated tank with no traces of ammonia or nitrite will help encourage your betta to swim and keep active.

You will be surprised at how active they can be in the right living conditions.

12. Strong Filtration

Bettas are not fond of strong currents in their aquarium which is usually produced by a filter. They naturally inhabit slow-moving waters with little to no water movement. If the current is too strong in the aquarium, your betta fish may spend more time hiding. Adjusting the filter flow will help encourage your betta fish to be more active.

bubbles of the oxygen air filter in the aquarium
Image Credit: lumosajans, Shutterstock

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In Conclusion

A healthy and happy betta fish will have no problem being active during the day. Some bettas might rest more than others, but they should still be swimming around afterward. Adjusting their environment and treating them for diseases when necessary will help keep your betta fish active.

Featured Image Credit: Khairil Azhar Junos, Shutterstock

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