Betta fish can be solitary creatures, often hiding away in the dark corners of their tank. So do betta fish need light, and if so, what kind of light do they need?
Betta fish need a period of light and dark each day, just as they would have in their natural environment. The day/night cycle is not only important for their health, but their eyes have not adapted to see well in the dark.
Throughout this article, I will cover everything you need to know about the light requirements of betta fish, such as how much light a betta fish needs, what type of light is best for betta fish, and whether betta fish can sleep with the aquarium light on.
Do Betta Fish Like Light?
Betta fish do like to have some light in their tank, even though they often hide away in dark areas. Betta fish have excellent color vision, similar to humans, and light helps them to see the huge array of bright colors around them.
A common question I hear from betta owners is, can betta fish see in the dark? A fish’s eyes are made up of rods and cones. Some fish have more rods that help with night vision, and some have more cones that help with color perception.
Fish that live in deep water, away from natural light, have a greater need for night vision, so their eyes develop more rods. Fish with more rods usually have excellent night vision but see the world mostly in black and white.
Betta fish live in shallow water, where natural light (and moonlight) can enter the water easily, so the betta has developed more cones, creating excellent color perception but poor night vision.
Do Betta Fish Like Sunlight?
Betta fish like sunlight, but it is not necessary for their health. In the wild, betta fish often hide away in plants and dark areas to avoid predators. Sunlight does provide some essential vitamins, but a healthy diet can also provide them.
In their natural habitat, betta fish usually venture out into open water in the early morning or late evening when the sun is not as strong. UV light can damage their delicate skin and scales if the sun is too strong.
If you choose to put your betta fish tank in direct sunlight, make sure it has a cover to filter out harmful UV rays. It is also important to ensure the water doesn’t get too hot, as this can also be detrimental to your betta’s health.
Not only will sunlight affect the water temperature, but too much light can cause excessive algae growth in your betta tank, so it would be best to avoid direct sunlight when possible.
How Much Light Do Betta Fish Need?
How much light a betta fish gets can impact its sleep/wake cycle and overall health. In the wild, betta fish are used to a day/night light cycle of sunrise and sunset.
Betta fish need around 14-16 hours of light per day for good health. A regular cycle of light and dark helps a betta’s biological clock, which dictates sleep patterns and allows certain biological processes to occur.
You can achieve the correct amount of light for your betta fish by using artificial lighting that is set on a timer or by having a routine where you switch on the light when you get up and turn it off when you go to bed.
I have mentioned that too much natural sunlight can cause algae to grow, but too much artificial light can have the same effect. Allowing too much light into your aquarium can negatively affect plant life and fish.
I should also mention that if there is not enough light and you have a fairly dark tank, your fish and live plants will not thrive as they should. There is a fine balance between too much light and not enough light, which will depend on your setup.
Do Betta Fish Need Light At Night?
Because betta fish have poor night vision, you may wonder if they need light in their tank at night, so they don’t bump into things.
Betta fish do not need light at night, they should have complete darkness as this is mostly when they sleep. Betta fish are not completely blind in the dark as they are very sensitive to minute pressure changes in the water which helps them to navigate.
Like most fish, betta fish have pressure sensors dotted along a lateral line that runs the length of their body from nose to tail. These pressure sensors can detect minute changes in the water and sense movement, helping the betta to hunt for food and to swim safely in darkness.
Betta fish also have monocular vision, meaning that each eye acts independently, enabling them to track predators much better. Monocular vision is not good for depth perception, so a betta fish often relies more on sensing pressure changes in the water for navigation.
Can Bettas Sleep With The Light On?
Most fish lack eyelids, and betta fish are no different, so do betta fish sleep well with the light on or when the tank is too bright?
Betta fish can sleep with the aquarium light on, and they often do. Although betta fish will get most of their sleep during the night, they also sleep during daylight hours. Betta fish seem unphased by light when they want to sleep despite the lack of eyelids.
Betta fish also like a well-planted tank which provides them with areas to hide away, and it will also shade them from bright light when they want to sleep. Betta fish sometimes jump out of their tank when disorientated from a lack of sleep, so it’s always worth providing dark comfortable areas.
As long as you switch your betta tank light off at night to provide some darkness, your betta will be happy and help them remain healthy.
What Color Light Do Betta Fish Like?
Fish tank lights come in all shapes and sizes, and they also come in different colors and wavelengths. So what color light do betta fish prefer in their tank?
Betta fish typically prefer soft lighting that matches the colors of natural light, ranging from warm yellow light for sunlight, white muted light when it is overcast, and a subtle blue tone of light at night.
Led lights are perfect for most betta tanks. You can buy led lights in a wide range of colors, which can often be adjusted to suit.
Some led lights specific for betta tanks have harsh, luminescent colors, which are tolerated but not ideal for betta fish. When choosing aquarium lighting for your betta, it will be best to pick natural colors.
Fluorescent tubes are the most common choice for aquariums and have been used for many years before led lights were even invented. Fluorescent lighting is cheap but lacks led light’s features and longevity.
Below is a kelvin chart where you can find the different color temperatures of daylight. Using this chart should help when choosing your betta aquarium light.
When purchasing lights for your betta tank, they will display the approximate temperature in kelvin, which you can compare to the chart above. Although the approximate temperature of individual lights can vary slightly, they are usually pretty close.
In general, most betta fish like a light temperature between 6000k-8000k, which is in the white/blue range of light. If you are unsure, it is always best to err on the side of caution and go for a light that is not too bright and not too dark.
More expensive betta tank lights will emit all of the suitable light temperatures, which you can switch to when required.
How Bright Should The Light Be For A Betta Fish Tank?
The brightness of the light in a betta fish tank is just as important as the color temperature. If the light is too bright, it can cause your betta fish stress, often leading to health problems.
The light should be bright enough that your fish can see and swim comfortably without being blinded or stressed. A good rule of thumb is to have a light that is no more than 1-2 watts per gallon of water in your tank.
For example, a 10-gallon tank should have a light that is no brighter than 20 watts. If you are unsure, it is always best to start with dimmer light and increase the brightness gradually until you find a level that is comfortable for your betta fish.
Many aquarium lights will have a diffusion panel that softens the light and spreads it evenly around the tank. Diffused light is more pleasing to look at in a fish tank as it eliminates specular highlights and strong shadows.
You can create a diffusion panel to place over the light with some frosted perspex or a piece of thin white cotton. Ensure the light doesn’t get too hot before using cotton, as it will be a fire risk.
Remember that a light that is too bright can trigger an algae bloom.
Do Betta Fish Like Blue Light At Night?
When the warm yellow glow of the sun disappears, and the moon rises, the ambient light changes from yellow to blue. This color change is quite subtle but noticeable when you pay attention. So do betta fish like blue light at night.
If you want to keep your betta’s tank as natural as possible, you can provide a subtle blue light in the evening and dim it right down at night. Your betta will like this soft blue light as it won’t disrupt their sleep pattern or biological clock.
Most living creatures have a circadian rhythm which is affected by the color (or temperature) of light. Warm, yellow light signals daytime and wakefulness, and blue light signals that night is here and it is time to sleep.
Triggered by the circadian rhythm, certain chemicals and hormones will be released into the bloodstream at certain times of the day, so a blue light at night will help to keep these rhythms in check.
Betta fish are no different, and a blue light will help to keep them on a regular sleep schedule so they can be at their best during the day. If you don’t want to provide a blue light at night, that’s okay too. Your betta fish will do just fine without it.
Betta Fish Tank Lights I Have Used
If you want to purchase a light for your Betta aquarium after reading this article, I have provided a few recommendations based on lights that I have used myself or recommended to others with some excellent feedback.
Led Lights For Betta Tanks
Koval LED Aquarium Light (Check Price) – Various colors and settings, including a subdued nighttime setting of dim blue light. This betta fish light will rest over the top of your tank.
Chihiros WRGBII Slim Edition (Check Price) – Highly adjustable tank light which can be operated via Bluetooth and has a sunrise/sunset function.
Current USA Satellite Plus Pro Freshwater Aquarium LED Light (Check Price) – One of my favorite led aquarium lights for freshwater tanks. This light is controlled by a remote and has several light effects such as moonlight, overcast, lightning, and storm to help your betta feel like it is back with nature.
Each of the options above has various size options available and alternative recommendations.
The question “Do betta fish need light” is quite easy to answer, but there are many other considerations, such as how much light and what type of light betta fish need.
Many people believe that bettas prefer natural light, but betta fish don’t understand the difference between natural light and artificial light. The best aquarium lights are subtle and similar to natural light.
Betta fish do need light and a good period of darkness to keep their biological clock in good shape. The best type of light for betta fish is between the white-blue range of 6000k-8000k.
The brightness of the light shouldn’t be too high as this can cause stress to your fish. A good rule of thumb is no more than 1-2 watts per gallon of water in your tank. If you are unsure, start with dimmer light and gradually increase the brightness until you find a comfortable level for your betta fish.
Finally, if you prefer to keep your tank light on at night, you can add a soft, muted blue light to mimic the color of the light found in nature. The blue light will help your betta to rest if it is not too bright.