How to Take Care of Discus Fish?

Discus is a freshwater fish native to the flood plains of the Amazon. This fish is highly sought after by aquarists due to the unique disc-shaped body. Some may have a round or triangular body.

They can grow to a size of up to 8 to 10 inches. This makes them ideal for moderate size aquariums.

In this guide, you will learn how to care for your freshwater aquarium Discus fish with the help of some simple tips.

The guide also contains information about the ideal tank mates for the species.

Discus Fish Aquarium Requirements

Discus fish (Symphysodon aequifasciatus) are not recommended as pets for beginners due to the difficult care level.

The ideal aquarium water temperature for the fish is between 82 degrees F and 88 degrees F (28 C and 31 C).

Keeping the fish in cooler waters will increase the risk of disease. A quality heater is recommended to keep the water warm when the room temperature is low.

Aquarium water should be soft and slightly alkaline with pH levels between 6 and 7. You should not add tap water to the aquarium.

Use a de-chlorinator before adding the tap water to the aquarium. Reverse osmosis is necessary if water quality is highly alkaline. The technique is also recommended for hard water.

Acclimatization of Discus Fish

When introducing the fish, you should let the bag containing the fish float in water. Let it float for about 30 minutes to help the fish acclimatize to the new conditions.

This is important to avoid shock due to the drastic changes in water conditions. The fish will die if there is a significant difference in the water condition from where you bought the fish.

Another option is to ask the seller about the water conditions.

You must adjust the aquarium water parameters accordingly before introducing the fish. You should also add a deworming medication before putting the fish inside the aquarium. This will ensure a parasite-free tank for the fish.

You should quarantine new discus fish prior to adding with other fish. Look for signs of disease such as a white spot, bloated stomach, or lethargy.

Never mix a diseased fish with healthy fish. You should either return the diseased fish or treat the disease using the appropriate treatment option.

Aquarium Setup for Discus Fish

Discus fish require at least a 50-gallon aquarium. They are schooling fish, so you need to keep at least five of them in the aquarium.

Ideally, you should keep in a 70- to a 100-gallon aquarium. A large aquarium will provide adequate space to swim along with other fish. A tall aquarium is recommended to accommodate the unique shape of the fish.

Water flow inside the aquarium should ideally be slow.

You should consider breaking the flow of water by using vertical wood, but it should be placed in a manner that the discus fish is not injured as they swim inside the tank.

Discus fish spend most of the time searching for food at the bottom of the aquarium. That’s why the sediment should be soft and smooth.

Sharp sediments can injure the fish as they forage for food. Furthermore, you should place plants to decorate the tank.

This will help maintain the water quality and provide the oxygen necessary for the fish. Recommended plants for the aquarium include java fern, anubias, bacopa, micro swords, and sword plants.

Consider adding air stones to maintain oxygen levels. An airstone will prevent a dip in oxygen particularly during the hot summer months.

Additionally, you should have an air filter inside the aquarium, which will help in maintaining water quality.

Ideal Aquarium Mates for Discus Fish

Discus fish are mostly shy, and will not harass other fish inside the tank.

They get along well with the most peaceful and semi-aggressive fish. Ideal mates for the discus fish are other Amazonian fish. Some of the fish that can be best mates include:

  • Rummy-nose tetras
  • Neon tetras
  • Ember Tetras

Other fish that are ideal for the discus fish include Bolivian Rams, Gouramis, and Pencil Fish. You can also pair discus fish with Marbled hatchet fish and Sterbai Cory Catfish.

Discus fish should not be paired with aggressive fish. These include angelfish, oscar, jack the ripper, pufferfish, and betta.

You should also avoid pairing the fish with too large or too small fish. Larger fish can inadvertently eat the discus fish while smaller fish can be swallowed.

You can also pair the discus fish with shrimps and snails like Amano shrimp and nerite snails. But make sure that they are not too small otherwise they can be eaten.

Discus fish are schooling fish and are happy in a large group. They may start bullying each other if you keep a small group.

If you keep two or three fish in the tank, they might start displaying aggression towards each other. To avoid territorial aggression, you should buy 10 juvenile discus fish at the same time.

Feeding Discus Fish

Discus fish are omnivores that eat different types of food. The fish mainly eat algae and pieces of scrap food in the wild.

They also feed on anthropods and invertebrates in the wild. You can feed them insets, amphipods, copepods, and small invertebrates.

A variety of food items should be given so that they maintain their color. You should consider giving them different types of flake food like tropical fish flakes and spirulina.

Furthermore, you can feed shrimp pellets and algae to the fish.

Live food items are also great for discus fish. You can give them brine shrimp, mosquito larvae, and blood worms. These are important food items as they result in brightly colored fish.

Discus fish should be fed twice a day. When feeding the fish, you should make sure that all of them can eat. The fish have a pecking order and sometimes larger fish block the smaller fish inside the tank.

To ensure that all of them get to eat, consider dispersing the food at either side of the aquarium.

You should only give them enough food that they can eat in five minutes. Excess food should be cleared as it can break down and degrade the quality of water inside the aquarium.

Juvenile discus fish require a lot of feeding. Fish that are less than four months should be fed five times the amount fed to an adult fish.

Fish that are between four months and a year should be fed two times the amount fed to an adult. It is recommended to use an automatic feeder to feed younger fish.

Discus fish require a high protein diet. The daily diet should contain about 50 percent protein. You should feed them quality pellets and flakes such as the beef heart flakes that contain high protein content.

Moreover, you should give them frozen brine shrimp and blood worms, which also contain high protein content.

Common Diseases and Treatment

Discus is not a hardy fish. Freshwater fish can get various diseases. The most common disease is the Ichthyophthirius that is more commonly known as ich.

It is caused by a parasite that attaches to the fish’s body. A fish afflicted with the parasitic disease have white spots over the entire body. The fish may also rub against the tank or decoration and become slimy.

Treatment of the ich is possible using medications such as Malachite Green, Formalin, and potassium permanganate.

The disease is highly infectious so you may have to treat the entire aquarium instead of quarantining the fish. Increasing the water temperature may also speed up the lifecycle and kill the parasite.

Fin rot is another common discus fish disease. The disease is caused by a bacteria known as Bacteriosis Pinnerum.

At the onset of the illness, the fins of the fish may become opaque or white. The fins will then rot away over time. To treat the condition, you should administer Nitrofurazone, Acriflavine, or aquarium salt.

Improving water quality can also help in preventing the disease. Moreover, removing fish that nips the fins of other fish can also prevent bacterial infection.

Dropsy is a fatal disease that is difficult to treat. It is caused due to an internal bacterial infection. Symptoms of the disease include a bloated body, bulging eyes, and detraining scales.

You can treat the condition by adding bath salts, nalidixic acid, tetracycline, and penicillin. But treatment is not possible if the disease has progressed far.

You can keep the fish healthy by maintaining good water conditions. Dirty water generally leads to parasitic, viral, or infectious diseases.

Sometimes introducing a diseased fish bought from the market also result in a disease outbreak. You should take care and quarantine new fish before mixing with existing fish in the tank.


Discus fish require specific conditions to thrive. You should constantly monitor the water conditions to ensure that they are ideal for the fish.

They are sensitive to changes in water parameters. Changes in water conditions will cause stress that will make the fish susceptible to diseases.

Water should be tested daily using kits available in the online store. You should also clean the sediment using a gravel vacuum every week.

Moreover, you should change the water once a week to maintain water quality.

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