Why Is My Cardinal Tetra Losing Color?

I have been keeping aquariums for many years, and I love them! They are so calming, relaxing, and it’s enjoyable to watch all of the different types of aquatic creatures swim around your tank. There is nothing more beautiful than watching your fish dart around your tank, and it’s even more beautiful when you have a nice planted aquarium. But nowadays, my cardinal tetra is suddenly losing its color. Is it serious?

There are many reasons why Cardinal tetras might be losing their color. Mostly, cardinal tetras lose their color due to environmental stress, changes in temperature, water parameters, light intensity and duration, the introduction of new species to your tank, overstocking an aquarium with fish. Besides this, some fish might also lose their color due to diseases.

In this post, we will go over what you can do to make your cardinal tetra get its color back, and we will also talk about some diseases that could cause this.

How Does Cardinal Tetras Look?

Cardinal Tetras are a beautiful freshwater fish that is part of the Characidae family.

They have an orange and black coloration on their bodies with long, flowing fins. This makes them look very different from many other types of tetra species out there. They can grow to be about three inches in length, and they have a lifespan between four and five years.

Most aquarists use Cardinal tetras as pets for aquariums because of their unique coloration. But it is important to know how they look before you purchase them. Make sure that the cardinal tetra fish has bright colors on its body with no fading or blotches. If it does not, then you should avoid buying it.

Why Is Your Cardinal Tetra Losing Color?

There are many reasons why your cardinal tetra might be losing color. If you notice that the fish is not acting normally or becomes lethargic, these can both indicate illness. Moreover, some of the reasons why Cardinal tetras lose their color are:

Environmental Stress

Cardinal tetras need an optimum environmental condition to survive. Therefore, a change in the temperature of the tank, fluctuation in the pH level, or any other environmental change could lead to stress. This can result in loss of coloration for your cardinal tetra.

Poor Water Conditions

A cardinal tetra losing color may be due to poor water conditions, like ammonia or nitrate poisoning. One of the most common causes is an inadequate aquarium filter. Since Cardinal Tetras are usually very sensitive to changing environmental factors in their habitat, it’s easy for them to feel stressed out, which will lead to loss of color.

Cardinal Tetra Disease

If your Cardinal tetras are losing their color, it may be because they have a disease such as Ich or Neon Tetra Disease, which is common among many fish species and affects the skin and gills. This can also lead to other problems like white spots on the body, fin rot, and fungus on the body.

Poor Nutrition

Sometimes your Cardinal tetra might be losing its color due to the lack of nutrition in their diet. This is most likely if they are fed flake food that can sometimes contain more fillers than actual nutrients for your fish to thrive. If you notice that your Cardinal Tetras are losing their color, one of the best things you can do is switch over to high-quality pellet food.

Internal Parasites

Another reason your Cardinal tetra might be losing its color is that it has internal parasites or diseases that cause discoloration like methemoglobinemia, which is a condition where there isn’t enough oxygen in the blood.

Cardinal Tetra Reproduction Cycle

If your fish are losing their color, it could be because they’re going through their reproductive cycle and will sometimes act strange if this happens. During the breeding season, female cardinal tetras can become territorial around other cardinal tetras.

Cardinal Tetra Lighting Issues

If your Cardinal tetras are losing their color, it could also be because there is not enough lighting in the tank or too close to a light source which can cause stress on the fish.

Can Cardinal Tetra Get Back Its Faded Color?

The answer is yes. It can get back to its normal coloration, but it may take time for the fish to regain that natural beauty. Generally, discoloration of cardinal tetra happens because of some reasons. If you can identify the reason behind this issue, it will be easier to solve the problem.

Once you get rid of the cause of discoloration, your cardinal tetra will likely regain its natural color and beauty. However, if you notice this issue again in the future, try to figure out what caused it, then implement a solution accordingly.

Many people face discoloration issues with their fish tank inhabitants at some point in time or the other. This problem can be acute when they don’t take proper care of their fish tank.

How To Stop Cardinal Tetra From Losing Its Color?

One of the main reasons cardinal tetra fish lose color is when they feel stressed or fail to keep themselves in a proper environment. The following ways will help you prevent your cardinal from losing its beautiful colors

Keep Cardinal Tetras With Peaceful Tank Mates

Cardinals are very friendly fish. However, they are slow-moving fish, so that that other faster fishes might bully and nip their fins. Therefore, they should only keep with peaceful tank mates to prevent stress and loss of color.

Keep The Aquarium Clean

Poor water quality will make your cardinal sick or cause it to lose its colors. Keep the aquarium clean at all times. Ensure regular water changes in the tank.

Add Some Aquarium Plants

Cardinals are great swimmers, and they love to swim around the aquarium. Adding some plants will make them feel safe, secure, and more comfortable in their environment. They also provide shelter for your cardinal, which it needs as a security measure against other fish that might bully it.

Ensure A Proper Diet For Your Cardinal Tetra

A nutritious and balanced diet is the key to your fish’s health. The best option for you is to feed them high-quality flakes, pellets, or frozen food that contain all the necessary vitamins and minerals essential for their growth.

Avoid Overfeeding Your Cardinals

It would be best to avoid over-feeding your cardinal tetras because the excess waste will accumulate in your aquarium, which is harmful to your fish. Instead, feed them only the amount of food they can eat within a few minutes and remove any uneaten foods from the tank to avoid decaying in the water.

Include A Good Quality Fish Tank Heater In The Aquarium

Cardinals are coldwater fish, so you need to keep your aquarium at room temperature. If the water temperature is too low, your cardinal will lose its color, and it might even die. So, you need to have a good quality fish tank heater installed in the aquarium.

Include A Good Quality Fish Tank Filter In The Aquarium

You should also install a high-quality filter system in your aquarium for easy maintenance of the tank. If your filter system is not working correctly, the water will become cloudy, and you need to replace it as soon as possible.

It’s also a good idea to avoid using filtration media that contains activated carbon because they remove essential vitamins from the tank, which are important for the healthy growth of your fish.

What Should You Do When Your Cardinal Tetra Loses Its Color?

Cardinal tetras can quickly lose their color when they feel stressed or sick. So, if you notice that your cardinal is not looking good and it has lost its colors ultimately, there might be something wrong with the water quality of your aquarium. Poor water quality will make your fish sick.

Some of the things that you need to do if you notice your Cardinal tetra losing color are:

  • try to change at least 50 percent of the water in your tank every day;
  • Make sure that you keep up with doing partial water changes two or three times a week. This will ensure that there is no build-up of toxins and ammonia in the aquarium.
  • Check your aquarium for any dead plants. Dead plants can cause poor oxygen levels in your tank, and this will make fish sick too.
  • Check the filter for excess debris or waste material inside it. Make sure to remove all plants from the aquarium before starting a partial water change with tap water because these plants will not do well with chlorine in it.
  • Turn the filter off and remove your carbon pads from inside it before starting a partial water change process. These filters will remove beneficial substances (e.g., ammonia and nitrite) and leave behind harmful ones (i.e., chlorine and chloramines).
  • Do not overfeed your fish because excess food will result in high ammonia and nitrite levels inside the tank, which is harmful to your cardinal tetra.


How Long Does It Take For Cardinal Tetras To Regain Its Color?

A Cardinal Tetra won’t regain its color until it is healthy again. This can take between few weeks to several months, depending on the severity of the illness or injury that caused it to lose its color in the first place.

Can I Keep Multicolored Cardinal Tetras In My Tank?

Yes, it is possible to keep multicolored cardinal tetras in your tank. However, you will need a more extensive community tank when trying this method because they are an aggressive species of fish. If the other inhabitants do not mind them being around, then go for it! It can be fascinating to watch these types of colorful and active fish.


In conclusion, Cardinal tetras are also very peaceful and happy when in a larger school of around six or more individuals, so this would be another plus to having them in your community tank. They prefer living with their kind over other species of fish. Thus, it would help if you emphasized keeping them in groups whenever possible. If you have the space for it, try having a school of them in your home aquarium.

With proper care and consideration, the colorful cardinal tetra is a beautiful fish to have in your tank. They make great community inhabitants because they are peace-loving and will usually get along with other non-aggressive species of fish. Keeping them in schools will enhance their happiness as well!

Thanks For Reading!

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