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Do Betta fish need light? What about darkness? How many hours of each every day? If you’ve been asking yourself these questions, you’ve come to the right place to find the answers.

As fishkeepers, our goal is for our fish to thrive in their aquariums. Choosing the correct lighting and using it for an optimal number of hours each day is paramount to the health of our animals. A balance between darkness and light is essential to emulate a fish’s natural habitat. Betta fish naturally live in the shallow, standing water of canals, floodplains, and rice paddies in Asia. The shallow water Betta fish call home indicates they experience a more natural day and night light cycle when compared to deep-water dwellers.

Do betta fish need a light? Yes! Betta fish typically need between 8 and 12 hours of light and 12 to 16 hours of darkness each day. Make turning your aquarium light on and off a part of your routine after you wake up each day and before you go to sleep each night.

Keep reading to learn why darkness is just as important as the light for Bettas, how big your lighting should be, and why direct sunlight might be a cheaper but less safe option for your scaly charges.

Why Do Betta Fish Need Light?

Light is essential for Bettas for the same reason it is for you and me. Appropriate light cycles simulate the natural setting Betta fish call home and promote a healthy sleep schedule. Bettas need adequate sleep to remain healthy.

Like humans, Betta fish are diurnal, meaning they are active when it’s light out and inactive when it’s dark. Forgetting to turn off your aquarium light at night is like you trying to sleep when the sun is up. This can lead to a stressed out and over-stimulated fish, and stressed fish are much more susceptible to disease. This balance between light and darkness is called a Circadian Rhythm.

Sunlight vs. Artificial Light In Your Betta Fish Tank

Though many inexperienced fish hobbyists may assume natural sunlight is the better option for their fish, any fishkeeper with experience will tell you that artificial light is a much healthier option in the long run.

First off, the only way to utilize natural sunlight is to have a place where sunlight can reach your tank, most often by an uncovered window. The glass walls of aquarium tanks, especially smaller ones like those used for Betta fish, act as magnifying glasses. The sun can pass through the glass walls of the tank and heat the water to uncomfortable or even dangerous levels.

Natural sunlight can also cause algae blooms. Algae blooms are dangerous because they can negatively affect your water quality and lead to bacterial infections for your fish such as fin rot. Algae blooms can be kept under control by keeping up with your water changes.

If you choose to use natural sunlight to light your tank, be prepared to closely monitor water quality and temperature to avoid any hazardous fluctuations that could be harmful to your Betta fish.

How to Choose an Artificial Light for Your Betta Fish

If you’ve chosen to use artificial light to control the light cycle in your Betta fish tank, the diversity of lighting options available can be daunting. Like sunlight, the wrong type of light could lead to a rise in water temperature for your tank and adversely affect your fish.

Betta fish are most comfortable in water that is between 23 and 26 degrees Celsius (74 and 78 degrees Fahrenheit). The following are some options for aquarium lighting:

  • Incandescent bulbs: This lighting option is not recommended for aquariums. Incandescent bulbs give off a lot of heat and are highly inefficient.
  • Fluorescent bulbs: These are a cheaper light bulb option that is commonly used in fishkeeping.
  • LED lights: Though initially a higher cost than fluorescent bulbs, LEDs are cheaper in the long run due to their longevity. LEDs most closely resemble natural sunlight, do not encourage algae growth, and are much more efficient than either incandescent or fluorescent bulbs. LEDs are also the most aesthetically-pleasing option as they best highlight your Betta fish’s flashy coloration.

Be sure when choosing a light to select one specifically designed for aquariums. Light sources not made for use with aquariums can be deadly if they accidentally come into contact with the water. Betta fish are deft jumpers and may accidentally come into contact with the lighting.

What Kind Of Wattage Does Your Betta Fish Tank Need?

Unless you have a very large tank or plants with lighting requirements, chances are your tank only requires one bulb. A more complicated rule of thumb is to calculate 1 watt per gallon for an LED bulb and 1.5-3 watts per gallon for a fluorescent bulb.

Since the ideal tank size for a Betta fish is between 20 and 40 liters (5 and 10 gallons), one bulb, whether LED or fluorescent, is more than enough.

After installing a new aquarium light, watch your Betta closely for any changes in behavior, especially if you have a male. With lights that cause aquarium glass to reflect too much, a male Betta will view his reflection in the tank walls as a rival male and become aggressive. This behavior is characterized by “flare-ups” where the male puffs out his fins and rushes forwards,     and can lead to injury from running into the glass.

How Many Hours of Light Does Your Betta Fish Need?

Betta fish typically need 8 to 12 hours of light every day, and 12 to 16 hours of darkness. Betta fish getting too much light will show signs of stress as a lack of appetite. Some stressed Bettas may quit eating altogether. This can lead to serious illness as the immune system of your Betta becomes compromised.

Too much darkness can be just as damaging for your Betta fish. Without sufficient exposure to light, Betta fish tend to lose their vibrant coloration (be sure to rule out other possible factors such as pH level, temperature, and algae levels).

Without a light cycle that tells them when to eat and sleep, a Betta fish’s body clock can go out of whack. Balanced light and dark cycle is just as essential for your Betta fish as it is for you.


Using a Timer for Your Betta Fish Tank

By far the easiest way to ensure your Betta fish receives an appropriate amount of light and darkness each day, especially if you tend to be forgetful about turning the aquarium light on and off, is to install a timer. Automatic timers are relatively inexpensive and fairly easy to use. Simply plug the timer into an outlet then plug the aquarium light into the timer. Program your timer to your preferred light cycle, specifying what hours you would like the aquarium light to be turned on.

An added bonus to an aquarium timer is being able to have the aquarium light turn on and off on days and nights that you may not make it home to do yourself.

Do Betta Fish Need Light: A Summary

Choosing the correct lighting option for your Betta fish doesn’t have to be a confusing or stressful experience. Follow this checklist to make the best choice for your fishy friends:

  • Bettas need 8 to 12 hours of sunlight a day to ensure a healthy and balanced sleep cycle.
  • Artificial lights are preferable to natural sunlight. They give you more control of day and night cycles and lower your chance of overheating your aquarium water accidentally.
  • LED bulbs are the best option on the market. Though they have a higher initial cost, LEDs will actually save you money in the long run as well as provide your fish with the lighting closest to resembling natural sunlight.
  • Only 1 light is necessary for a typical Betta fish tank.
  • Automatic timers are cheap, simple to program, and easy to use.

Hi, my name is Jordan. I've been in the fishkeeping hobby since my childhood. Welcome to my blog where I help fishkeepers enjoy the hobby by offering free guides, advice, & product reviews. Read more...