Do Betta Fish Need Light? LED Light or Sunlight? (2024 Guide)

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Dr. Mollie Newton
Published by Dr. Mollie Newton PHD| Senior Editor
Last updated: June 6, 2024
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Imagine drifting off to sleep in your bed peacefully, only to have your essential sleep disrupted by a jarring, bright light precisely at 2am. Surprisingly, such confusion and disruption are just as distressing for a fish!

Article Summary

  • Betta fish originate from the tropical rice paddies of northern Thailand and are accustomed to natural sunlight in their daily cycle.
  • Too much light can lead to overstimulation and stress in betta fish, causing health and behavioral issues.
  • Not enough light can make betta fish lethargic and affect their feeding habits.

When answering the question “do betta fish need light,” the answer is yes, but only as much as most other animals do. What I mean by this is that betta fish prefer a natural light setting with a consistent day and night cycle.

Leaving your fish under the cover of darkness for too long can make them lethargic. That is why I highly value a nice quality light for my betta fish.

While the finer points of choosing exactly the right timing, variety, and quantity of light in your betta fish tank can seem like an overwhelming task, we’ve taken the time to research just what you need. Follow along for more!

Why Do Betta Fish Need Light

bettas need consistent day and night cycles to remain healthy and happy…

Originating in the tropical rice paddies of northern Thailand, betta fish must obviously be accustomed to plenty of natural sunlight in their daily cycle. The potential danger comes from the artificial addition of too much or too little.

As a diurnal fish species, bettas need consistent day and night cycles to remain healthy and happy…

In general, fish use the absence of light to signal that it is time for them to sleep. This is simulated in your betta tank by removing whatever artificial lighting you have on and allowing your fish to enjoy a nice, dark tank.

Bettas in their Natural Environment

Betta Swimming Through Plants
Betta Swimming Through Plants

Bettas in the wild often have to cope with wildly changing conditions ranging from monsoons to major dry seasons where they must live in shallow standing waters. As such they have developed several intriguing adaptations to survive in the wild.

These fascinating fish have adapted to breathe air thanks to a specialized organ called a labyrinth, making them members of the suborder anabantoidei.

For wild bettas, hopping between shallow bodies of water can still be dangerous, but as long as they have had sufficient exposure to water they can survive periods of up to 5-6 hours at a time on dry surfaces.

How Much Light Do Betta Fish Need

Betta fish need light about as much as most other fish you’ll see in the average aquarium. In the rice paddies of the fish’s natural habitat they get a normal cycle of day and night depending on the season, and will enjoy this in your home as well.

Try not to lease your betta aquarium in direct sunlight, as this can lead to overheating of the water temperature within your tank and be dangerous for their health. Too much heat means that their natural body processes will be overworked as they attempt to cool and compensate.

In terms of how many watts, this can range from 100-400W at the high range for a high-powered aquarium light

How Many Hours of Light Do Betta Fish Need

When trying to plan aquarium lighting around just how many hours of light your betta’s tank needs, we recommend that you consider the natural light cycles of their native habitat of Southeast Asia.

A typical daily cycle in the tropics is around 10-15 hours of sunlight, with the rest ranging from dusk until true darkness.

At a minimum, consider having your betta tank light on for 8-10 hours at a time to allow your betta to have a safe sense of what a consistent day feels like. Betta fish typically feel the most at home with a constant pattern of light and dark.

Effects of Too Much Light

Multicolored Light
Multicolored Light

Too much light can be incredibly harmful to the health of your betta fish. The two main concerns are that this can cause overstimulation and stress, both of which can lead to serious health and behavioral complications for the betta.

Not to mention potentially harmful algae growth can become an issue in an overlit tank.


When there is too much artificial light or natural light in your fish tank, bettas can have a difficult time knowing just when they need to rest, when they should be active, and when they should eat. This can lead to them becoming overactive and stressed as they struggle to cope with the inconsistency.

Over time, this constant stimulation can exhaust your fish. This may cause some, especially male betta fish, to act with increasing aggression towards other fish or even themselves as they attempt to charge their own reflection!

Signs of Overstimulation

  1. If you notice that your betta is often trying to engage with its own reflection, consider the use of an aquarium paper background to block out the appearance of the other betta!
  2. If you notice that your fish is lethargic, moving slowly or exhibiting odd behaviors such as swimming towards the top of the tank this may be a sign that it has been overstimulated and is receiving too much light.


In general, stress is the response an organism has to any environmental hazard or inconsistency.

In fish, stress can cause a wide variety of health problems and can even lead to death if not responded to in an adequate amount of time. You may even find your betta not moving and sometimes the answer will be stress.

One of the more damaging effects of stress caused by aquarium lights is not eating. An overstressed fish will be too busy trying to understand its environment to feed itself consistently, and can starve as it is having a difficulty knowing when it’s supposed to be fed.

A stressed fish may become more predisposed towards illnesses and bacterial infections, such as fin rot. Tiny holes can begin to form in the fins of the fins, leading to loss of function over time.

Betta Tank Effects of Too Much Light

Considering that most people like to have more than just bettas in their fish tank, there are a variety of effects of too much light for others.

Live plants, a natural betta buddy, can enjoy the benefits of both direct sunlight and artificial light, but may become damaged by the added heat.

Additional aquarium light can also encourage algae growth and even lead to a harmful algae bloom if unmonitored. This can decrease the overall amount of oxygen in your tank and lead to serious problems for betta fish.

Effects of Not Enough Light

Betta Fish In The Dark
Betta Fish In The Dark

In contrast, too much darkness can also lead to problems for your betta fish. They may become lethargic as they try to sleep more than they need to, or have difficulty eating or stop eating altogether since they normally feed during the day.

As stated previously, while there is no technical minimum of daily light required for betta fish, they should be able to achieve a natural sleep cycle with around 8-10 hours of darkness each night.

This will allow your fish to get the normal amount of sleep a wild betta would get, while still being reasonable for the average aquarium owner to achieve without using a timer.

Consider the use of an aquarium timer to maximize the efficiency of your artificial tank light. This not only ensures a consistent schedule but takes the hassle out of having to remember yourself!

Are Betta Fish OK in the Dark?

In general, your bettas will do better with more darkness than too much light, but they still need their natural cycles of day and night in order to be as healthy as possible and avoid being sick.

Even if they were nocturnal, they would still need a regular amount of tank light to simulate natural sunlight and signal that it is time for them to sleep.

Should I Turn Off My Bettas Light at Night?

Absolutely! As we’ve been suggesting throughout this article on aquarium lighting, we recommend turning off your betta fish light to simulate a natural evening and help them achieve a normal healthy sleep cycle.

Can Betta Fish See in the Dark?

Can Betta Fish see in the dark?

The answer to this is yes, but not very well.

As a fish that is normally active during the daytime, bettas have not developed particularly strong night vision and typically need light to see where they’re going and what they’re eating.

Unlike the humans, betta fish possess what is called monocular vision, meaning that each eye is capable of seeing its own image, rather than working together to produce a single picture.

Surprisingly, thanks to this monocular vision betta fish have difficulty with depth perception and must use their body’s lateral line to sense movement in prey through changes in pressure in their surroundings.

Betta fish have a difficult time seeing red light, which can be important when considering led bulbs. A difficult time seeing translates to a hard time eating and surviving!

What Kind of Light Do Betta Fish Need

Betta Fish Near Rocks
Betta Fish Near Rocks

In general, we recommend artificial light over natural sunlight. When fully exposed, it can be difficult for your bettas to avoid direct sunlight which can cause them to overheat.

When selecting an artificial light we recommend looking for one that comes with an internal timer, which can make things much simpler when setting up your betta fish tank.

Any tank light can work, including fluorescent lighting. The key is to make sure that your artificial lights do not produce too much excess heat.

Tank lights that don’t come with a built-in timer can be modified with a plug-in socket, adding much utility to an aquarium light that may be more affordable.

Does My Betta Fish Need Sunlight?

While betta fish don’t technically need natural sunlight in order to survive, we can use artificial light to best simulate what they would get in their natural habitat.

Just because your betta fish doesn’t need a particular kind of light source doesn’t mean that it doesn’t still need light to see its food and surroundings!

Are LED Lights OK for Betta Fish?

As with most other sources of artificial light, a led bulb can absolutely be used for your tank. These lights can make for an inexpensive alternative to fluorescent bulbs or incandescent bulbs as they draw much less power while still not passing additional heat into the aquarium water.

Even colored lights in colors such as blue, yellow, and green can work with this kind of setup, turning your tank into a neat decorative room light!

Just remember that all fish need light in order to make the best use of their surroundings.


Hopefully reading through this article has helped you come to a conclusion regarding the question “do betta fish need light?”

Our general answer is that when considering betta fish light try to aim for something that is consistent in the day and night cycle and best mimics their natural environment, as this can help your fish live their happiest, healthiest life in your home.

Feel Free To Share!

As always, thanks for reading along with us today and we wish you the best of luck on your aquarium journey!

If you’ve found any of this information useful please feel free to share it with the other aquarium enthusiasts in your life.

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