Does Bright Light Make Betta Fish Turn White?

Betta fish are known for their vibrant colors. They are the most attractive in any fish tank. That’s why you should be alarmed when the fish showcases several white or discolored spots. If you have recently changed the aquarium lights, you must be confused whether it’s possible for bright lights to turn a betta white.

Bright light doesn’t affect the betta’s skin color directly. But it causes stress; which eventually leads to such discoloration. It doesn’t happen overnight. In most cases, betta fish showcases such symptoms after being exposed to harsh lighting for a long time.

We know it sounds horrible. But don’t worry. You can heal the fish. But to do that, you first need to know how bright lighting affects a Betta. You will find all that information below. So, without further ado, let’s get started.

Key Takeaways

  • Being exposed to harsh lighting for long time can lead to skin discoloration.
  • But the discoloration doesn’t happen overnight and can always be reversed.
  • However, bettas also lose vibrant stripes due to age, bacterial diseases and so on.
  • Harsh UV light can cause skin diseases in a Betta too.
blue yellow color gorgeous betta
Owner: Jody Tourand

Is Bright Light Making My Betta Turn White?

Skin discoloration sounds like a disease. And it makes no sense that bright light would cause such a condition. But the truth is, lighting is an important aspect of betta keeping. And, no, we are not talking about their eyesight only. It’s related to the whole health, including skin color.

Harsh lighting can actually hurt the Betta’s eyes. The condition gets even worse if there is no plant or decoration to hide behind. All the poor fish can do is swim back and forth. It increases their stress level. But as we said, only one day’s exposure to harsh lighting doesn’t cause discoloration.

To be this bad, the lighting should be ON for at least a few months. Apart from the sudden white spots, there are several other symptoms to identify the issue much earlier. The fish will have difficulty sleeping & eating. Why it can’t sleep shouldn’t be hard to understand. Bettas require subdued lighting to rest properly.

The excessive illumination inside the tank doesn’t help in any way. And it’s common for Bettas to stop eating if they feel threatened inside the tank.

Another symptom is Lethargic behavior. You will see the happy betta suddenly go quiet and moody. It might create a small nest and stay inside it the whole day. You will only see the betta coming out of its cocoon once the lights are OFF. That’s how you know it was actually the lighting system that was bothering them.

See also  Why Did My Betta Fish Change Color From Blue To Red?

How Much Brightness Is Comfortable To The Betta?

Now that you know your Betta tank is too much let’s find a comfortable range. 4-5 watt LED lights are okay if your tank size is 5-8 Gallons. If it’s an incandescent bulb, you would need more watts per gallon. Incandescent lights are quite dimmed. So, there’s less chance of hurting the Betta’s eyes.

But the problem with incandescent or halogen bulbs is that they produce too much heat. We don’t want the aquarium water to get too warm, do we? It’s okay to get LED lights if you know which one to pick. Since these lights are extremely efficient, an increase in 1-2 watts can result in extreme brightness. Take a quick look at this chart.

Tank SizeLED (watt)Incandescent Light (Watt)
5 gallon5-watt 30 -watt
10 gallon12-watt 60-watt
20 gallon15-watt 100-watt
40 gallon32-watt 200-watt
gorgeous white betta
Owner: Jessica Spivey

As you can see, there is no fixed “watt” for a certain tank size. It depends on what type of lighting you are choosing as well. If you have a 5-gallon tank, don’t go beyond 30 watts for an incandescent bulb. However, if you switch to LED, the power requirement will be much less. Imagine bringing a 30-watt LED bulb for a small betta tank.

A small misunderstanding or lack of knowledge can put your fish in a very uncomfortable situation. A 32-watt LED bulb can generate 3000 lumens. However, we only need around 400-450 lumens for a 5-gallon tank. That’s how your tank ends up with “too much light.”

Even though some fish don’t mind white light, Bettas prefer not to have glaring harsh lighting.

Does UV Light Make A Betta Fish Turn White?

UV light doesn’t have the general “brightness” we see on every other kind of lighting. But that’s for us. UV light’s spectrum is below the human’s visibility range.

However, the case is different for a Betta. It can easily see ultraviolet rays. That’s why it’s important to know whether the invisible lights are too harsh or not. for that, you have to rely on what the manufacturers say. As long as the radiation is termed UV-A (within 380-370 nm), it shouldn’t be too intense.

Since we have addressed stress, let’s talk about colors. Colors with long wavelengths are rarely visible to a Betta. So, it doesn’t matter. However, while dealing with blue or violet, you have to keep track of your Betta’s behavior. Blue is an overstimulating color and often leads to hyperactivity & stress. But some aquarists argue that Bettas love blue lighting over the bright white LEDs.

We believe it depends on your Betta entirely. If you choose to use blue or violet lights, see how the fish reacts.

Why Does My Betta Turn White In A Large Tank?

According to some aquarists, betta fish loses most of its color in larger community tanks. Once the fish is transferred into a smaller tank, its skin color starts improving. What’s the matter here?

See also  Do Betta Fish Like Color-Changing Lights?

Well, no evidence shows Bettas hate larger tanks. However, if you mean a community tank by the word “large,” there is an explanation. The problem with Bettas is that they are never too friendly with the tank mates. You need to be careful choosing friends for a lonely betta. There are lots of fish, including Goldfish, which get a hostile reaction from a Betta.

That’s why leaving a Betta inside a large community tank can affect their health negatively. The constant stress from defending its territory would lead to discoloration. You see, stress doesn’t only come from lighting sources or the water condition. You have to go to the root and solve it for good.

The only solution we can offer is to transfer the fish to a separate tank. The size doesn’t have to be as big as a community tank (of course). We recommend at least a 4 to 5-gallon tank for one mature Betta. Trust us. Please remember you are not isolating the fish from its underwater friends.

In fact, you are saving it from the potential bullies. Plus, by nature, Betta fish doesn’t like living in groups. Experienced Betta keepers even report that multiple Betta fish (male) in one tank can lead to nasty fights, including death. That might be the reason your Betta’s skin issue starts improving in a smaller but single tank. It’s all because of less stress. Now you know.

red betta fish close up
Owner: Jenseng Tea

What Are Some Other Possible Reasons?

It’s possible that bright lighting is causing white spots on the Betta. But there are other possible reasons with higher chances of being true. Take a look, please.

1. The Betta Is Too Old

The expected lifespan of a healthy Betta fish is 3 years. If it has been over 3 years since you bought the Betta, you know what’s coming. The Betta has lived its life and is moving towards death. And, at the last stage of life, it’s common to look pale. Not just discolored/white fins, the Betta fish might showcase saggy skin, black spots etc.

 It is a confirmation that the Betta is sick and might die eventually. Unfortunately, there’s nothing much to do in this case.

2. Your Fish Is Infected

It’s hard to believe. But even after such intensive care, a Betta fish can be infected. And those small white spots on the Betta are a warning before your fish loses its life. Here are some common diseases which lead to discoloration or white patches on the body.

3. Ick

Ick or Ich, whatever you call it, is a parasite attack. The parasite is invisible to human eyes and acts like a fish louse. But it is only a matter of time before the single parasite multiplies itself. That’s when the fish starts acting weird. You will see it become restless and always trying to scratch against the sand. Luckily, it’s curable. All you have to do is stick with regular water change. Don’t forget to ask for medications from your vet.

See also  Can You Keep Betta in A 3-Gallon Tank? [And is It a Good Idea?]
Name of diseaseIch
ReasonParasite attack
SymptomSmall white spots, fish trying to scratch against anything.
TreatmentMedical dosage, along with regular water changes.

You really need to make sure a Betta is not infected with parasites before dropping it in a community tank. We suggest you keep it in a separate tank for a while.

Owner: Jenseng Tea

4. Betta Fin Rot

Fin rot is a painful disease some Betta go through. The name of the disease is pretty much self-explanatory. The fin starts to “rot,” & the condition keeps spreading all over the body. The initial stage is noticing white spots on the body. It usually happens when a lot of toxins are present in the water.

Water parameters must be at an ideal range for the Betta to stay happy. When you don’t have a filter on the aquarium, the tank water can get filthy pretty soon.

Name of diseaseFin rot
ReasonUnfiltered tank
Symptom white spots along with unusual fluffiness.
TreatmentUse aquarium salt, filter the water regularly.

 The treatment is cleaning up the tank, of course. Do a partial water change and examine the water condition thoroughly. If multiple Bettas are in a tank, quarantine the affected one ASAP.

You Have Chosen A Low-Protein Diet

People often don’t treat Bettas like a carnivore. It’s because they have a great appetite and would eat almost anything. For example, if you are giving it veggies, the fish will munch on it quite happily. That misleads many hobbyists to believe that organic veggies should be added to Betta’s diet.

The fish needs a protein-based diet. You must add as much meat as you can get, be it organic or manufactured. Even the pellets made for Bettas have almost 70%-80% of crude protein. That’s what is natural to a Betta. They don’t need to eat veggies to fight constipation. If your betta loves cucumbers, give it only once in a while. But keep the quantity low so it doesn’t interrupt their daily dosage of protein.

Protein-based diet is responsible for the vibrant stripes on a Betta.

The Water Contains Harmful Substances

If you don’t have an active filtration system on your Betta tank, it can easily accumulate harmful substances. We are referring to chemicals like nitrate, ammonia, etc. An active aquarium system makes sure the ammonia is removed from the water as soon as it’s added.

If you plan on manually changing the water, your fish might have to stay with those chemicals for the time being. And not every Betta has the same tolerance, right?

The same can happen with a changed pH level, temperature, and even the minerals level. Hard water is extremely dangerous for Bettas.

Before You Leave!!

You are very late if your Betta already has white spots on its body. It’s important to figure out the lighting issue sooner to avoid such a condition. Have you ever noticed your Betta preferring darkness over light? If so, then it’s a pre-symptom that your lighting system is too harsh. To get a deeper insight, check our article on “Why is my betta fish swimming in the dark and not in the light?”

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Muntaseer Rahman

About Author

Hello, I’m Muntaseer Rahman, the owner of I’m passionate about aquarium pets like shrimps, snails, crabs, and crayfish. I’ve created this website to share my expertise and help you provide better care for these amazing pets.


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