March 14

Sarah Robertson

Why Is My Betta Fish Turning Black?

Betta fish, also known as Siamese fighting fish, is a fish that has become popular as a pet in recent years. Almost everything about this fish is fascinating. They come in a vast array of colors, shapes, and have interesting personalities.

However, there is one concern that many betta fish enthusiasts are concerned about: "why is my betta fish turning black?" Because this issue has a variety of causes, the answer isn't simple.

This is a common occurrence in betta fish. There are many things that can make your betta get this hue, including the type of food you feed it, the environment it's kept in, or if its fins are torn or diseased.

The best thing to do when your fish turns into black color is research whether this may be normal for that particular breed and/or if there are any other symptoms prior to doing anything drastic like changing out the water.

'why Is My Betta Fish Turning Black?'- What Are the Reasons?

The common causes of Betta turning to black are-

Temperature Changes

If the temperature of your aquarium water increases or decreases, you might find that your betta fish is becoming dark in color. It is because the change in water temperature affects the physiological functions of the pet. This also reduces its immune system forcing it to take in a dark color.

Genetic Factors (Marble Gene)

There are some betta fish breeds that have a genetic mutation which is commonly referred to as Marble Gene. This gene makes the bettas lose their natural color. If your betta has this gene, it may turn black in color due to its genetic makeup.

Inappropriate Water Conditions

Water quality is paramount in keeping your betta fish healthy. Poor water conditions may cause you to see black color bettas. This can be caused by either change in temperature or water pollution.

Repetitive Stresses

Bettas are very sensitive pets and even the slightest sound, movement, or anything that they find strange can cause them stress. Even their living conditions and tankmates may injure or irritate them. This makes them turn black in color. However, the intensity depends on how long the stressor has been going on.


The reason betta fish turn black can be because of being sick. Whether it is a bacterial infection or fungal infection, a disease, or a parasitic infestation, all these agents attack the fish's immune system.

What Type of Disease Causes a Betta Fish to Turn Black

What Type of Disease Causes a Betta Fish to Turn Black?

If you see that your betta is turning black, then one thing that comes to mind is whether it is suffering from a disease. There are many diseases that can cause bettas to turn black and they need to be treated as soon as possible or else you might lose your pet.

Black Spot Disease

If your betta fish has black spot disease, it is very likely to turn black in color. The disease causes parasites to attack the fin area which makes them dark. Black spot disease is caused by parasitic infestation and can be treated with the help of a medicated fish food that you can buy from your local pet store.

Ichthyophthirius (Ick)

This affects the outer layer of your pet's skin and body making it look dark under the microscope. This disease is commonly called Ick and the best way to deal with this is by following a quarantine period of 30 days. This kills all the parasites while your betta fish rests in peace, without having contact with other fish.

Fin rot

When the fins of your pet turn darker colors it could be because they are infected with fin rot. The disease causes deterioration of the tissue in the fin, therefore turning them dark. It is important to check with your aquarium store whether the fins are infected or not before you start treating your betta fish.

Bacterial Disease

There are some bacterial diseases that affect bettas making them turn black color. This includes mouth rot disease which damages the membrane in its mouth making them dark.

Bacterial Bloom

If you will notice your betta fish in black color it could be because of bacterial bloom. This develops due to nitrites or ammonia present in the water. You can check your aquarium's water quality with test kits available at pet stores.

To treat Betta Fish Illness: You need to make sure your fish aquarium water is clean and well maintained. The water temperature should not fluctuate much. You need to ensure that your betta fish gets all the nutrients in its diet.

Tank That is Not Cycled

If you notice that your betta fish is fading color, then it could be because of the tank not being cycled. Bettas are very sensitive to water conditions and changes in temperature can also cause them stress.

Does Age Make Betta Fish Turn Black?

It has been noticed that bettas get color loss as they grow older. Even though this is true, it is not a specific fact rather just a simple observation.

Is Black Betta Fish a Bad Sign?

If your pet is turning black, there is no need to worry. In most cases, it is not a sign of death or anything related to that. It is just a color variation that you can easily treat by changing the environment of your aquarium and caring for it as usual.

Can Injury Make My Betta Fish Change Color?

Yes, injury can cause your betta fish to change color. Not just that, it can also change the way it looks. It may appear very different from normal and this is because of stress.


If you overfeed your betta fish, then it is very likely that they will develop diseases. In addition to that if they turn dark, then it could be because of stress due to overfeeding. Overfeeding can also cause constipation and a lack of nutrients in the betta fish.

What Should I Do if My Betta Is Turning Black?

Adjusting the Water for Bettas

The easiest way to make sure that your betta fish does not turn black is by adjusting the water conditions. This means making sure that your aquarium is cycled and you maintain its temperature at a steady level.

Feeding the Right Kind of Food

Change the food you give to your pet, as it can be responsible for turning it black. This can also affect the color of its fins and body.

Replacing the Water

Just like changing food, replacing water can change your betta fish's color as well. You should not do it too often though, but just when you feel that your aquarium needs cleaning or you want to change something about it.

Add a Betta to a Healthy Aquarium

One way of making sure that your betta fish does not turn black is by adding it to a healthy aquarium. This means an aquarium filled with clean water, which has been set up for at least 6 months and is kept in good condition.

Quarantine the Betta

You can quarantine your betta or you can check if it is healthy by visiting your local fish store. You can also buy an aquarium kit online and follow the instructions given carefully to set up an aquarium for your pet.

It will be safer than having it in a new environment, which makes it vulnerable to diseases. Black bettas are very common and easy to treat. It is not a sign of death but just means that your fish needs some extra care. If you are willing to give it the time it deserves then there are no problems with your pet turning black.

Eliminating Stress

Stress is one of the major causes of any fish turning black. In order to get rid of stress, you need to change the environment and give them enough time to settle down.

Providing Enough Oxygen

Just like humans, bettas need oxygen to survive. If the amount of oxygen is less in water, it can be one reason why your betta's color is turning black. This means that they might not be getting enough oxygen and you need to check out your aquarium set up or change something about your tank if required.

Make Sure The Tank Is Big Enough

If you have a small tank, then it can also be the reason why the color of your betta fish is turning black. So make sure the tank is big enough and provides all the conditions required by it.

Make Sure They Have A Heater And Filter

Having a heater and filter is also very important. Without the right temperature and filtration, your fish cannot survive for long.

Feed Them Color Enhancing Food

You might want to try making your Betta happy by feeding them color-enhancing high-quality food. They are readily available at any pet store and you should not have to spend too much on them. It will also make it stronger and healthier, which is always a plus point for bettas that turn black.

How do I Get my Betta Fish its normal Color Back

How Do I Get My Betta Fish Its Normal Color Back?

If you want your betta fish to color back then one method is providing it with a new environment that will not stress it out. Make sure the water conditions are good and everything set up by you is perfect for your pet.

It is very common for bettas to turn black and this does not mean that there is anything wrong with it. You just need to make sure that you give it time and everything required by it. A small change in the environment can make a lot of difference in how your pet looks, which is completely normal in most cases.

Do Bettas Get Darker as They Age?

Bettas, just like any other living organism on Earth, will change as they age. This means that your fish can also become darker as it grows older.

However, if you feel that the color is different than normal and does not seem to be going back to its original tone then it might be a sign of a disease or an illness. You should try and treat it as soon as possible before the situation gets out of hand because black bettas can be very dangerous for your other fish in the same tank.

Do Betta Fish Change Color?

Yes, betta fish do change color depending on their mood and surroundings. You can try changing the colors of your betta by adding new images or objects in the aquarium. This will make them think that they are in a different territory and it might also affect their behavior throughout the day.

In some cases, you might be able to notice a change in the shade of the betta depending on how it feels at a certain time. If you can provide them with a good environment and treat them well, then there is no need to worry about anything going wrong. Bettas are very friendly and unique fish that can adapt to any condition as long as they receive love from their owners.

What Does It Mean When My Betta Fish Turns Black?

If your Betta fish suddenly turns black, it may indicate some underlying problems like fin rot or ich. However, it is also possible that the changes in color are caused by stress during transport or new tank mates.


Betta fish can turn black for a variety of reasons, but the most common ones are stress or an environment that doesn't suit their needs. When you notice your pet's color changing to this shade and it doesn't seem like they're going back to normal, make sure you treat them as soon as possible with medication before the situation gets out of hand.

Some points to remember:

Some Betta fish lose their coloring naturally, such as the Marble Betta.

Unless your Betta is showing other signs of illnesses, you shouldn’t worry overly much if they begin to turn black.

Your Betta’s coloring can be improved with high-quality, color-enhancing foods.

Clean tank. Maintaining good water parameters and not overstocking your tank with too many fish.

Sarah Robertson

I am a passionate blogger who also happens to be a fish keeping enthusiast. Writing about my hobby is something that I absolutely love to do, and it's no secret that my chosen topic is always centered around fish keeping.

Sarah Robertson

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