Do Betta Fish Need Light

Do Betta Fish Need Light ? [Answered]

Keeping our fish healthy is of utmost importance to all of us, but how much do we understand about what they need? Often we give little thought to the consequences of not providing an ideal environment for our fish to grow in.

Fish, just like humans, do require a healthy environment, free of contaminants and other extreme environmental conditions for them to maintain their mental as well as their physical health.

One key factor that determines how healthy your fish is, is the amount of light, both natural and artificial, that you expose it to. Providing too little or light that is too harsh can severely damage their temperament, their appetite, and physical health.

Hence it is important to learn about the ideal habitat for each fish and simulate that environment as realistically as you can. Different fish will usually have different requirements.

Ensuring that you provide an adequate amount of light for your fish for the right number of hours a day is critical to their growth and development.

I’m sure you must have a lot of questions now. Don’t worry, keep reading and we’ll work through every question that you may have. Let’s get started.

Do Betta Fish Need Light

Betta Fish

The Ideal Type of Light For Your Betta Fish

When it comes to lights for your fish, you’ve got a couple of options. The most critical point to remember is that you should aim to replicate your fish’s natural lighting conditions.

Now Betta fish are tropical fish that don’t thrive in deep water. They are found in the shallow waters of the rice paddies in Thailand. Hence, their biology is attuned to receiving natural sunlight throughout the day, which is what’s best for them.

So you need to ideally aim to approximate lighting conditions to as high a degree as possible. The higher you do, the better it’ll be for your Betta fish.

So should you Just Keep Your Aquarium Out Under The Sun?

Keeping your aquarium out into the sun may not be the best idea. There are a couple of reasons that justify this.

Excessive Algae Growth: Excessive sunlight can give rise to an exponential growth of algae in your tank. This will not only make your container dirtier and foul your water but can also potentially cause serious bacterial infections in your fish. If you do decide to keep your tank out in the sunlight (not recommended), do make sure that you perform regular cleanups to remove the likely excessive algae growth.

Excessive Heating: Another major problem that continual exposure to sunlight is that it will excessively heat your tank over time. This excessive heat will also raise the tank’s water temperature significantly and this is definitely not good for your Betta fish’s health. Additionally, over-exposure to direct sunlight results in a significant amount of UV rays entering the tank. Prolonged exposure to such intense UV levels can damage your Betta fish’s eyes.

Artificial Lights – A Great Alternative
Your Betta fish don’t necessarily need sunlight for survival. They can survive just as well in artificial lighting conditions.

You have quite a few options as far as which type of artificial light to use for your tank. Choosing the right kind of light is extremely important. The wrong choice can present serious health hazards for your fish.

With that out of the way, let’s look at your options :

Incandescent Bulb: Incandescent bulbs are not suitable for your Betta fish. They are incredibly inefficient. They also have high heat-to-light production ratios, resulting in a high amount of heat generated for every relatively smaller unit of light. Hence, incandescent bulbs can heat your fish tank quickly, which in turn can be potentially hazardous for your fish.

Fluorescent (CFL) Light Bulbs: Fluorescent bulbs are a much better option and are suitable for your Betta fish.

LED Lights: We’ve saved the best for last. LED bulbs are the best option when it comes to artificially lighting your aquarium. They are extremely affordable and have low heat-to-light production ratios. Simply put, they are extremely energy efficient and imitate natural lighting conditions to a high degree.

Thus, do get LED lights if possible. If not, stick to fluorescent bulbs but please don’t use incandescent bulbs under any circumstances.

FAQs- Do Betta Fish Need Light

Do Betta Fish Need Light Throughout The Day?

Betta fish

No, they don’t. Periods of darkness are just as important.
Just like every other living being, Betta fish also need to be able to maintain a daytime/nighttime routine.

These fish operate on a rhythm known as the circadian rhythm just like us. The circadian rhythm is a natural cycle that dictates us to go to bed when it gets dark and to wake up when the sun comes up.

Following the circadian rhythm is critical to ensuring that your Betta fish stay healthy. So make sure to turn off the light in your tank before going to bed. This routine will help them run on their internal biological clock which helps them know when to wake up and when to sleep.

Do Betta fish have night vision?

Betta fish can see in relatively darker environments such as muddy waters, but their vision is not attuned to absolute darkness. They can look in opposite directions simultaneously but are not attuned to permanent changes in lighting conditions. Hence they prefer to sleep during the night.

So For How Many Hours Should You Keep The Light Shut?

You should ideally aim to keep the light on for around 8 – 12 hours a day and keep the light shut for another 12-16 hours a day. This ensures optimal conditions for your Betta fish to have a healthy sleeping routine.

What Are The Consequences Of Over Or Under Exposure To Light?

Overexposure to light can result in your fish being over-stressed. As a result, its appetite is likely to decrease drastically.
It can also weaken your fish’s immune system and thus make it more susceptible to various diseases.
Underexposure to light makes your fish lose their colors which is a sign of failing health.

Power Requirement For Your Betta Fish Aquarium

Typical aquariums for Betta fish have volumes lying in the range of 5 – 10 gallons. Thus, they are relatively small in size and don’t need intense levels of light.

If you have a large tank like the 40 Gallon breeder tank, then you will want to access the correct power requirements for it.

A good measure would be 1 watts or less per gallon for LED lights, and 1.5 – 3 watts per gallon for fluorescent bulbs.

Do make sure you don’t buy huge bulbs or lights that are too intense unless you have an abnormally oversized tank. Also, keep a lookout for a change in your Betta fish’s behavior upon installing the lights.

Execute regular checks to determine how comfortable your fish are with the lights you’ve been using. Use lower power bulbs if you see signs of aggressive behavior in your fish.

For The Most Forgetful Of Us – Use an aquarium lighting Timer

Are you someone who forgets your tasks quickly? If you are then don’t worry as this happens to a lot of us, especially as we progress in age.

I understand how difficult it is to keep a check on all your regular tasks, especially if the task has not yet been ingrained into your daily routine.

However, turning off the light in your tank before you go to bed, is one activity that you should treat with utmost caution. Forgetting to turn off the light can have grave consequences on your fish.

This is precisely why I recommend using a timer. A timer is a device that automatically operates the light in your tank. All you need to do is to set up the timer according to the time you want it to either switch on or switch off the light.

It is relatively affordable and saves you plenty of the hustle of switching the light on and off manually. A timer will ensure that your fish stay healthy even when you’re not able to attend to them.

To Summarize

All of this information can be overwhelming, and you may even be rushing out the door to get a new light as we speak. So, here’s a summary of all the main pointers:

Avoid placing your tank in direct sunlight for a long duration. Instead, opt for artificial sources of light.

LED lights are your best bet when it comes to artificial lighting. LEDs are affordable and don’t generate a lot of heat. They are followed by fluorescent bulbs which also do a decent job at lighting your tank. Avoid incandescent bulbs at all costs.

Make sure that you maintain a regular daytime/nighttime cycle. Fluctuations in the schedule can have grave effects on your Betta fish.
Use a timer if you want someone else to take care of switching on/off the tank light. A timer does that job brilliantly.
Keep regular tabs on how your fish are responding to their environment. Change the light immediately if you notice erratic mood swings.


Yes, Betta fish do need light for not just survival, but also their overall health. We must make it a priority to provide the most optimal lighting conditions according to their needs. This guide will help you make the right decisions and will ensure that your fish receives the best lighting that it possibly could have.

References and Citations

Pet Advocacy Network: CARING FOR YOUR BETTA

Petshoods: Do betta fish like light? Betta Fish Tank Colored LED Light