Do Betta Fish Sleep? When and How Long? (2024 guide)

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Dr. Mollie Newton
Published by Dr. Mollie Newton PHD| Senior Editor
Last updated: May 11, 2024
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Betta fish are certainly well-liked inhabitants of aquariums, often leaving novice fish hobbyists with numerous inquiries. It’s crucial to discern whether your siamese fighting fish exhibits regular sleep cycles as it directly pertains to their overall wellbeing. Continue reading to learn how you can enhance the sleep patterns of these magnificent water beings.

Article Summary

  • Betta fish do sleep, and they may appear still, floating, or resting in various positions during their sleep.
  • Betta fish sleep in short bursts throughout the night, and they don’t sleep for extended periods due to their territorial nature.
  • Each betta fish may have its preferred sleeping positions and locations, so it’s essential to observe their behavior and provide suitable resting spots.
Betta at the Bottom of the Fish Tankk
Betta at the Bottom of the Fish Tankk

How do betta fish sleep?

You might have noticed your betta is not eating, being extremely still, and floating or laying in one spot at night. This is likely because they’re sleeping. But if it’s for consecutive days or extended periods of time, it might be sick or might have ingested the wrong food.

When sleeping, bettas become extremely still but their eyes stay open because they do not have eyelids. They may even lose color when sleeping but they will rapidly regain it when they awaken. The loss of color is speculated to be a defense mechanism so that bettas are less visible to predators.


If color doesn’t return to your betta once they wake up it could mean they have a disease or are sick.

Unlike some sleeping fish, betta fish do not need to move when they’re asleep, this quirky sleeping behavior often scares new betta owners. Bettas can burrow into the substrate, lay on one side, float, or vertically float with their head down while sleeping.

Where do betta fish sleep?

Betta fish do not have a preference for where in the tank they like to sleep, just wherever they feel safe. You might notice bettas sleeping in or on tank ornaments, laying on the aquarium plants, nestled into the tank substrate, or even just floating in place. Many fish keepers have a betta log, live plants, or a leaf hammock to provide an area for their sleeping betta.


If aquarium plants are close to the surface of the water your betta could actually sleep “out of the water.” This is because bettas are labyrinth fish and can actually breathe air. However, it can not do this for long and will need to stay moist the entire time it is above the water.

Your betta chooses where it will sleep based on where it feels safe. In their natural habitat which is rice paddies, bettas love to hide amongst the leaves of plants or find caves. If your betta loves a certain spot try to keep that area the same to build normalcy and routine even when changing out other tank decor.

Bettas sleep in odd places, I’ve even had one sleep behind the filter intake pipe in my tank. I had to turn down the filter intake flow because it was slowly sucking at my betta’s slime coat.

How much sleep do betta fish need?

While bettas are very light sleepers and will rest in short bursts the exact amount of sleep they need is unknown. There is no perfect formula for how long your betta needs to rest and it will vary between individuals.

However, to get proper rest betta fish need to have a light/dark cycle with darkness being 50-67% of the time (12-16 hours). These fish need their beauty sleep!

In other words, if you have aquarium lights you should turn them off at night so it doesn’t interrupt your betta’s circadian rhythm.


Circadian rhythms are based on the body’s internal clock and is driven by a 24 hour period that is reset everyday by the sun’s light and dark cycle.

When do betta fish sleep?

Bettas sleep throughout the night in short bursts. Because they are territorial fish it is their natural instinct to not sleep for long periods in case something encroaches on their territory.

If you’re a new betta owner that is trying to catch a sleeping betta fish you might have to wait a few days after introducing them to the tank for them to settle into normal behavior. If your betta is sleeping you should try your best not to disturb it with your movement.


You should NEVER poke bettas while they are sleeping. It will startle it awake and activate its flight or fight response. It might take a long time for your betta to feel safe in their aquarium afterwards.

Do betta fish sleep with the light on?

No, in order for your bettas to have a healthy sleeping pattern they should be in darkness 12-16 hours of the day. The easiest way to make sure your betta is getting enough hours of darkness is to place a timer on your fish tank light so that it turns off and on at the same time each day.

If you notice your betta sleeping during the day then there is likely a stressor at night that should be removed ASAP.

How long do betta fish sleep?

Surprisingly, the total amount of time that bettas sleep throughout the day is unknown. They usually sleep in increments of roughly 20 minutes at a time.

How often do betta fish sleep?

Like humans and other land mammals, bettas sleep every day to stay alive. This helps replenish their energy and allows their organs to process food and waste.

While most bettas sleep during the night time they will occasionally take short naps during the day just like you and me.

Bettas likely sleep at night because that is when they can not hunt. This is a result of coming from tropical southeast Asia where they depend on differences in light and color to find their prey.

Betta Staying Still
Betta Staying Still

Why does my betta sleep so much?

If you notice your betta fish sleeping for several hours throughout the day there is likely something interrupting their sleep at night. You should address this problem as soon as possible to make sure your betta stays well-rested. Here are a few reasons that your betta fish is sleeping more.

Tank is too cold

Cold temperatures can cause a sleepy betta. As tropical fish, when the water temperature drops below an acceptable range they tend to go into temperature shock and enter a sleep-like comatose state as their heart starts pumping slower and there is less blood flow.


Water temperature is an important aspect of fish keeping, not just keeping betta fishes. Almost as important as keeping your tank clean, providing fresh water and feeding your fish. If your other fish are having trouble sleeping it could be caused by abnormal temperatures.

Aquarium light

If your light is on too long, not long enough, or is too bright it could cause your betta fish’s circadian rhythm to become messed up. This can also happen if your fish is placed in a brightly lit common area where lights are on all night. If you see your betta sleep at the bottom of the tank or in a dark corner this might be the cause.

However, if your betta tank is too dark your betta will likely not be happy because there are not enough hours of daylight or natural light for it.


Too much light in an aquarium isn’t just bad for a betta, it can also cause increased algal growth which can eventually cause problems with the water parameters, and even take up so much oxygen it can kill your fish!

Bored, sick, lazy, or old

You might have an old betta or a just plain lazy betta. A new betta fish could be bored with the tank environment or battling some sort of disease such as fin rot or swim bladder disease.

If you think your betta fish might be bored or not getting enough exercise throughout the day, adding toys for betta or decorations that they can interact with might help.

Large fins

These beautiful fish are known for their ornate fins but sometimes they can cause issues. When compared to bettas with shorter fins, fish with long fins tend to sleep more because of the huge amount of energy it takes to pull their fins through the water. In fact, you might notice that ones with long fins are particularly lazy bettas because of their fins.


You might notice that your male betta fish is sleeping more than your female. This is likely due to their larger fins. As bettas have entered the aquarium trade, breeders selectively breed betta fish for those with larger and more decorative fins despite the effects on the health of the fish.

Why my betta doesn’t sleep?

If you notice your betta fish sleeping a lot during the day it’s likely because something is interrupting their sleep at night. Here are some common causes of betta fish sleep loss.

Too much light

If your betta tank is in a common area like the kitchen or a dining room that is exposed to light for too many hours or your tank’s light is constantly on, your betta fish’s circadian rhythm is interrupted by an abnormal light cycle. But how much light is too much for your betta? Your betta should have 12-16 hours of darkness and 8-12 hours of light to get a full night sleep and keep your betta happy.


Light exposure doesn’t just come from tank lights, your betta can be overexposed by its tank sitting close to the TV or by a window. Before getting your betta you should plan where you want to place it’s tank and actively record the light patterns it will be exposed to.

Stressed by Overcrowding

Betta fish are territorial and semi-aggressive. Choosing the proper tankmates for your betta’s tank is important to ensure that it feels safe and secure enough to fall asleep.

Too much activity

If your aquarium is in a common area where people are walking by it often your betta fish sleep will be constantly interrupted because of the high amount of activity/stimulation.


In most pet stores betta fish have abnormal sleeping behavior because of the mass amount of overstimulation. Once you bring them home it will take a few nights in their new environment to establish a routine.

How do betta fish look when they sleep?

Sleeping Betta Fish
Sleeping Betta Fish

When sleeping your betta could be laying or floating on its side, upside down, or buried in substrate. Many betta owners often panic if they see their first betta sleeping because they assume it’s dead. However, sleeping bettas still need to breathe so before panicking look at their face and gills and make sure they’re opening and closing rhythmically.

Each individual fish will sleep in different positions and places. A new fish might prefer a spot that a previous fish hated. When helping a new betta adjust to the aquarium, observe the areas it likes to hang out in and offer different items for it to use as a bed (leaf hammocks, logs, etc.). Do not be offended if your betta chooses to sleep somewhere else entirely.

Do betta fish close their eyes when they sleep?

Betta fish don’t have eyelids so their eyes remain fully open even when your betta sleeps.


In the dark betta fish have relatively poor nightime vision but have great color vision.

Do betta fish move when they sleep?

You might see the occasional fluttering of fins while your betta fish is sleeping but otherwise there should be no movement except for the opening and closing of the mouth and gills. When your betta fish enters a deep sleep their breathing will become very slow, this is completely normal as it doesn’t take as much energy to maintain bodily functions when they are sleeping as it does when they are awake.


In conclusion, if you see your betta fish staying in one spot for short periods of time throughout the day or night you shouldn’t panic. They are probably taking some well-deserved rest to support their health and development.

Like all good fish keepers, you should monitor your siamese fighting fish sleep behavior to ensure they are not over or under-sleeping due to various unknown stressors.

Thanks for reading! Feel free to share this article with all of your friends and loved ones.

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