Do Discus Fish Change Color? If yes, Why?

I recently filled my aquarium with discus fish, and I was surprised when my discus fish started to change its color. It was then that I came across some interesting reasons as to why a discus changes its colors.

So, can discus fish change their color? Generally, a discus can change color to blend in an environment, for example if it is in a planted tank then there are high chances for it to change color. Among other factors, stress and fright are two MAJOR reasons why discus fish change their colors.

It is important to look at the main factors in detail as it can help us discover the reason behind their discoloration.

Discus changing colors (Video)

Factors that result in change of color of discus fish

Following are some reasons that cause discus fish to change its color:

  • Stress
  • Fright
  • pH and temperature
  • Age
  • Food


It is one of the main reasons why most of the discus are known to change color. This stress can be caused by inappropriate means of changing water or due to shifting or adjusting in a new environment.

It can result in discus losing their appetite that further weakens the immune system and their defense mechanism. High stress escalates chances for bacteria to attack discus, and hence causing discus to get sick.


Discus enjoy a stable and comfortable environment; hence any kind of movement, shadows or unnecessary poking can frighten them resulting in discoloration. The location of the fish tank should provide discus a peaceful and a relaxing ecosystem just like their home in Amazon.

Furthermore, lighting in the discus tank should be dim and calm according to the requirements of the discus.

pH & Temperature

The pH and temperature changes when water of the fish tank is changed. This change is intolerable for discus that causes it to change its color. It is important to monitor any kind of changes in pH level and temperature on a daily basis in order to provide a stable environment to the discus.

The ideal temperature range for discus fish is 82-86 degrees Fahrenheit while the pH should be maintained within 6.0-7.0.


Discus are known to reach their vibrant colors at roughly 5 or 6 years of age. This is why you shouldn’t be worried if your discus look a bit dull than the others during their first few years after birth.


Less intake of high protein food is one of the reasons that can cause discoloration in discus. Therefore, food variety and combinations can play a vital role in keeping them beautiful as well as healthy.

How to ensure that your discus have bright colors?

It is essential that discoloration is closely monitored by discus fish owners time to time, there are certain considerations that should be kept in mind to ensure that discus fish is taken care of.

  • Housing Requirements
  • Food Choice
  • Behavior and Compatibility

Let’s further explore these in detail.

Housing requirements

Discus desire their space; therefore, it is important to provide them a suitable environment that makes them feel like their home and keeps them stress free.

Therefore, they can be easily combined with vegetation such as foreground and long stem plants like Silvinia, Pistia or Anubia. A large and a tall aquarium with dimensions of at least 3 feet is ideal for them. You can also add driftwood, fine grain sand, rocks or even keep the tank bare-bottomed.

The water capacity, on the other hand, should be at least 10 gallons per discus; a 50-gallon tank would allow you to keep roughly 5 discus fish.

Favorite food choices

Discus are omnivores and can eat plants as well as meat.

The food given to discus should be in variety especially for best coloration. They prefer live, frozen as well as processed food. Blood worms, flakes, glass worms, vegetable shreds, algae rounds, beef heart etc. are some of their favorite items.

They can be given in combination, too. However, at times some black worms can cause discus to be unwell due to parasites and bacteria present in them. They can also be fed dry food that is ready made and available easily.

Monitoring the Behavior and compatibility of a Discus

The nature of discus is calm and social; therefore, they love to live with similar species. They are known as schooling fish as they are the happiest within groups. However, there are high chances for a discus to be stressed when paired with larger species.

Their suitable aquarium mates are neons, clown loaches, cardinal tetras, rainbow fish, dwarf chichlids, corydoras and rummynose tetras etc. Furthermore, they are likely to be aggressive during spawning.

Future recommendations for discus fish owners?

These are some recommendations for the discus fish owners in order to avoid discoloration in future:

Give recovering time to discus

When a discus fish is first kept in a tank, it should be given time to de-stress by adjusting, or in other words, blending in the new environment of the aquarium. During stress, discus hides itself. Therefore, there should be plants or unsharp rocks to allow it to de-stress.

Maintain and control temperature and pH level

Discus prefer warm and acidic water. The temperature that is optimum for a discus in an aquarium should be between 82°F – 86°F (28°C-30°C). The pH level, on the other hand, should be between 6 to 7, as anything more or less than this range can cause stress resulting in discoloration.

Check ammonia levels

Discus are ammonia sensitive, therefore, if there is ammonia present in the water, then there are highly noticeable changes in its color as well as its breathing pattern. If this is the case, an immediate water change is required.

Avoid chlorine

The water in the fish tank is usually filled with tap water that contains chlorine. High or low levels of chlorine can kill the discus fish therefore it is important that water used is de-chlorinated.

The location and the aura of aquarium

The aquarium should be kept in a place where it is less disturbed and quiet because a discus is easily intimidated by sounds, lights, and sudden movements. Moreover, the aura of the aquarium should provide discus a healthy foliage of their natural habitat which is similar to their home in Amazon.

Also, there should be enough space in the aquarium for the discus to freely roam around.

Related Questions

Is it important to keep track of the color change of discus? Any change in color should be taken into account, as it helps to identify the real reason of discoloration. For example, stress or unhealthy food can cause them to turn black. However, it does revert back to its original color once it is de-stressed or when other factors such as water, pH levels, temperature or ammonia is controlled.

What should discus fish owners do to avoid discoloration?It is recommended for them to emphasize on cleanliness as it is one of the most important areas to consider while keeping discus as a pet fish. A discus is sensitive to an unclean environment. Bio-debris can be formed in an aquarium as a result of food or fish excreta, therefore, unwanted mess should be properly dealt with, from time to time. Furthermore, there are high chances of fish diseases too as a result of an unhygienic environment such as rapid breathing, ick, discus plague, flicking, tail rot etc.

How to monitor the behavior of the discus fish?It is important to observe the nature of your discus; they might be calm but aggressive as well especially during the breeding process. On the other hand, one dominating discus has a high chance of creating risk and tension in an aquarium. Therefore, it is advisable to have a group so that the non-dominant fish does not die due to stress.

What is the most preferable flow of water for discus?The water flow in the aquarium should have a slight moderate flow with some current as a discus is used to slightly murky waters of Amazon. Therefore, strong water flow is not recommended.

How important is changing the water? There should be a constant routine to change the water of the aquarium weekly as discus are famously known to be ‘messy feeders’; not changing the tank’s water regularly results in growth of nitrates in the water which is harmful for the discus.

What are the things one should keep in mind, before keeping a discus?Discus is known as the ‘King of the Aquarium’, therefore it demands all the attention and care. It is known to be among the top favorites for fish lovers as they add beauty to the aquarium because of their magnificent colors.

However, a discus is known as a shy and calm fish that enjoys its own secluded territory. Therefore, keeping a discus requires care and construction of a well-adapted aquarium. All the discus fish owners should realize the importance of a suitable aquatic vegetation environment and diet as it plays an important role in color development of discus.

It is further recommended to have basic knowledge beforehand related to their development and care so that it makes the process of taking care of a discus easier.


Other sources

Leave a Comment