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

blue white gorgeous betta fish

Bettas are known for their beautiful vibrant colors. Do you own any blue Bettas and suddenly see them turning red? Are you wondering why such a thing happened? 

Your Betta fish may change its blue color into red due to certain illnesses, stress or aging. There isn’t actually one single reason for this. Various causes like age, genetics, health, environmental factors are responsible for it.

Now, if you want to know why your Betta fish is turning red from blue, and also find out possible prevention and solutions, I got you covered. Go through the article till the end.

Why Is My Betta Turning Red?

It is very possible for a Betta fish to undergo a natural color change as it ages or due to its genetics. Water parameters, stress or diet can be environmental factors for your Betta to turn red. 

In the following paragraph, I will try to describe some natural and unnatural causes of Betta changing color:

1. Genetics:

As I previously mentioned, genetics are a natural cause for Bettas to change from blue to red. Bettas are known for their wide range of color genes. Some variations can be more dominant than others. Over time as they age, these genetic variations can be more or less prominent, which leads to the change of their coloration. 

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For example, red Bettas that turn red will have red eyes and red fins too.

2. Age:

Many fish change their color throughout their lifetime. The natural coloration of Bettas happens when they age about 2-3 years. As they age, their colors become more vibrant or change. But younger Bettas mostly do not display their full color until maturation.

3. Environmental Factors:

Bettas are known for their vibrant colors. But factors like water quality and lighting can impact their coloration. The environment of the tank can be controlled by regular temperature checks, water changes, pH maintenance etc. A Good environment is an important condition to keep Betta’s vibrant colors intact.

4. Stress:

Bettas can change their color in response to their mood or stress level. It can be, they become paler or darker due to the interactions they make with their tank-mates or their emotional state. Stress can be caused by a wide variety of reasons.

One of the most common scenarios is a bright-colored Betta turning red/purple when they get angry. This behavior can be seen mostly when Bettas are in a overcrowded tank sharing space with aggressive tank-mates. Bettas send signal to their owner that they’re unhappy, by turning red.  Lack of oxygen can also be another reason for Betta’s stress.

5. Illness:

Illness can be an underlying cause of Betta’s change in color. Bettas may face health issues like fungal and bacterial infections.

One of the common fungal diseases for Betta is red spot disease. A fungus called Aphanomyces invadans. Sometimes bacteria can cause this disease as well. Bettas develop red spots all over their bodies. Sometimes the disease gets worse and the fish can become entirely red. This disease is dangerous because it can kill Betta fish within a few weeks.

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Another disease that causes redness in Betta fish is Hemorrhagic Septicemia, which is also known as Red Pest Disease. The bacteria called Pasteurella multocide causes this.

6. Ammonia Poisoning:

A heavily stocked aquarium can create nitrified bacteria and debris which then end up building ammonia. Ammonia is a poison that can burn the gills of Betta. thus Bettas can turn purple/red or even bleed.  Tank water becomes cloudy and fish become sluggish due to ammonia poisoning as well. 

blue black mixed color betta fish
Owner: Claire Bird

What Should You Do If Your Betta Turns Red?

Now that you know the reasons your Betta fish can turn red, you may wonder what you should do when it happens. Don’t worry, I’ll help you with some solutions.

Always focus on all the fishes of the tank if you suspect some sort of illness in a single Betta. If only one Betta turns red, the reason is its coloring due to aging, which is natural and genetic. But you can suspect illness if other Bettas show symptoms of redness. In this situation, you may take action according to the following steps:

1. Quarantine The Ill Fish:

You must protect your other fish from the ill fish to stop the disease’s spread. That’s why you should quarantine the ill fish in a separate tank for at least one week or more. This is a crucial step because fungal and bacterial infections are contagious.

2. Check Up On The Water Parameters:

While you quarantine for seven days, you should also regularly check up on ammonia and nitrate level of the original tank. If the ammonia level is above 0.5 ppm, you should change the tank water partially. The rule of thumb is to change 15-25 percent of the water weekly. But do not abruptly replace the tank water because drastic water changes can be uncomfortable for the fish.

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Keep the water pH between 6.8-7.5 because this is the most suitable for Betta fish. This may also help them fight fungal and bacterial infections and stress. 

betta fish eating
Owner: Frankie Hernandez

3. Eliminate Stress:

lack of Oxygen can create stressful condition for Bettas. And stress causes them to turn red. Keep Bettas away from aggressive tank-mates as Bettas are territorial in nature.  Also, create hiding spots with decorations. Here the rule of thumb is to keep one Betta fish for every 20 gallons of water.

4. Adjust The Temperature:

the perfect temperature requirement for Bettas is between 75-80⁰F. So try to keep it between that because maintaining temperature is a vital thing. If your room temperature is below 75⁰F, you can adjust it by placing a heater on the tank. 

5. Return The Betta To The Main Tank:

If you’re done keeping your Betta quarantined for one week, now it’s time to check the fish’s condition. If all the parameters seem okay, you can safely put your fish back in the original tank.

Final Words

I hope the above discussion will help you if your Betta Fish ever changed its color from blue to red. Apart from the natural causes, usually stress and illness are the main reasons for their color change. Thus, always try to maintain a healthy environment so that your Betta fish can stay happy and stress-free.

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Muntaseer Rahman

About Author

Hello, I’m Muntaseer Rahman, the owner of AcuarioPets.com. 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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