Do Betta Fish Like Light? Do They Need it at Night?

Wondering if betta fish like light? This guide is for you!

Betta fish originate from the tropics – places of abundant sunlight, such as Cambodia and Thailand. So, yes, betta fish need light, although this is not a matter of life and death for them.

However, your betta fish at home does need to survive on sunlight. Therefore, it will thrive on any form of warm light you provide for it in the aquarium.

Betta fish need a light that mimics the flow of a natural day. Therefore, it should be turned on during the day and turned off at night. This enables your betta fish to remain in touch with the natural day-night cycle, which is vital for its physical and mental health.

If you use natural plants in the aquarium, they’ll need light to carry out their natural cycles and thrive. Providing the night-day cycle in the aquarium keeps everything well-adjusted and balanced.

betta fish light

Does Your Betta Need Light at Night?

As noted above, bettas are natives of the paddies of tropical lands in South East Asia. Their original habitat comprised shallow ponds that could quickly evaporate under the intense summer heat.

To survive, bettas were forced to keep jumping from puddles to ponds.

During the day, the bettas would be exposed to overhead sunlight that provided them ample sunlight.

Darkness would set in at night, marking the time to sleep, relax, and rest. The point is, bettas’ evolutionary instincts have primed them to obey the natural flow of light during the night-day cycle.

Since they need to sleep when the sun goes down, they don’t need light at nighttime in the aquarium. So your betta will be happy with about 15 hours of sunlight during the day.

However, this pet will also need hours of darkness to mark nighttime. You can install timers to control the on/off functions of the lighting system in the aquarium.

The timer will switch the light off at night and allow your betta fish to rest and conserve energy.

Natural or Artificial Light – Which is Better for Your Betta?

Artificial light is the best option for your betta in the home aquarium. The problem with exposing direct sunlight to the aquarium is that it will make temperatures skyrocket.

This will mess up the lives of your betta and the plants in the tank. At the same time, sunlight encourages algae growth, which will likely compromise your pet’s health.

All your betta fish and the plants need is UV light, which can be provided by artificial lighting. UV light benefits both fish and plants and doesn’t carry the danger of heating up the aquarium.

An adequately installed artificial light will provide the much-needed Vitamin D for your pet. You may also use UVB lights (if your aquarium is big enough) or LED.

So, the answers are apparent regarding sunlight or artificial light. You should not keep the aquarium near the direct sunlight line.

Can Too Much Light Harm My Betta?

As the old adage goes, too much of anything is poisonous. Unfortunately, this is very true of the amount of light you expose your betta fish to.

We have established that your betta needs light during the day and darkness at night. However, ensure that you don’t overexpose him to too much light.

Too much light will cause more harm than good. For example, the betta will stay active because they haven’t received the signal to stop and rest.

In the long run, bettas that remain too active are likely to get agitated, stressed, and suffer fatigue.

Also, too much light makes the betta overstimulated, which may force them to stop eating. Overstimulation leads to stress and a host of attendant problems.

Providing too much light in the tank can cause chaos to your betta’s usual way of life.

Not Enough Light – What Happens?

Everything should be done in moderation when it comes to keeping betta fish. Problems are bound to occur if anything is done or given either in excess or meanly.

Your betta fish need just the right amount of light to maintain the beautiful color of its skin. Light keeps your betta’s colors alive and vibrant.

The absence of light or too little of it makes your betta look weak, dull, and lackluster. This is more so if other factors come into play.

These include poor temperature control, wayward pH levels, and algae bloom. Combined with poor light, these factors will wreak havoc on your betta’s beautiful life.

How Much Light Does My Betta Need?

Your betta fish is happy when you expose him to lighting conditions that mimic the day/nighttime cycle.

This is the betta’s natural environment, and you should try to follow it as closely as possible. You can do so by installing a timer that allows 12 to 16 hours of sunlight daily.

The same timer would allow 12 to 8 hours of darkness, giving your betta time to relax and recoup lost energy.

However, it would not harm if you reversed the timing to provide 12 to 8 hours of light and 12 to 16 hours of darkness.

To Leave the Betta Light On or Off At Night?

If you have followed the flow of this post so far, you know that the light should be off at night. But, more importantly, you understand why this needs to be the case.

Leaving the light on for too long makes your betta over-stimulated, which is bad for its overall health and wellbeing.

However, the light should be switched off as soon as it is daytime. Frequent delays in switching on the light may result in your betta fish losing color.

Also, don’t expose the aquarium to direct sunlight, as this will be counter-productive to your efforts to provide a good life for your pet.

Direct sunlight raises tank temperatures to dangerous levels. It may threaten the life of the fish and the aquatic plants in the tank.

Life in the tank will thrive under artificial light instead of direct sunlight. Using artificial light does not in any way encourage the growth of algae that would give rise to infections and diseases.

Some bettas are known to act aggressively when the light is on. The most logical explanation for this behavior is that they see their own reflections, which they perceive as rivals.

If your betta behaves this way, look for a way of constructively distracting him whenever you turn on the light.

Sunlight or a Heater – Which is Better?

The water temperature in your betta’s tank needs to be well-regulated. Temperature, like water pH, is a sensitive thing and often means the difference between life and death.

Your betta fish must live in a tank temperature between 240C and 290C (750C and 800C). Anything below or above these temperatures will kill the betta, or seriously compromise its life.

Subjecting the tank to direct sunlight will likely mess up this temperature arrangement, putting your betta’s life in danger.

The only way to maintain this temperature range is to install a self-regulating heater.

This constantly keeps the water temperature under the ideal conditions for your betta’s continued growth and happiness.

Ensure that you fit the tank with the right heater model. Then, shop carefully, considering the reviews of verified previous purchasers.

Also, have such a heater professionally installed so it can function optimally. Finally, have a backup plan in case the heater breaks or starts to malfunction.

Which is the Best Light for My Betta Fish?

As we have established, your betta’s tank should not be exposed to direct sunlight. The best light for your betta fish is artificial light.

The best artificial light is the one made for your tank. This light is designed with the size and dimensions of your betta tank in mind.

The light should be strong enough to cater to the needs of your betta fish. This should be in the region of 1 watt per gallon for LED lights.

For fluorescent lights, the ratio should be about 2 to 3 watts per gallon. Anything above these measurements is likely too strong and may cause your betta to be stressed.

Do not be afraid to seek professional help when buying and installing the lights. For example, you can ask someone in your local pet store to guide you on the best source of these lights.

Alternatively, look for professional installers online, and approach them for suggestions.

Betta fish tank manufacturers and sellers will have a good idea of how you can get any accessories to go with the tank.


Bettas like light because they cannot thrive in an environment of 24 hours darkness. Light syncs their internal clocks, and the bettas know when to play, eat, and rest.

But, as with everything else to do with your betta fish, the light should be given in moderation. Too much or too little of it will likely turn your betta’s life upside down.

Also, artificial light is preferable to natural in the aquarium because sunlight creates unfavorable temperature conditions.

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