Beginner’s Guide to Getting Started with Discus Fish

Discus is one of the most beautiful and incredible freshwater tropical fish with a very unique body shape. It won’t be wrong to say that it is the king of the aquarium because it is as graceful and majestic as a king! This beautiful fish draws the attention of aquarists towards itself like no other fish can.

There is a reason why Discus is called the king of the aquarium. Mostly it is because of the fact that it requires great care and attention as compared to the other freshwater fish. If not given the “royal treatment”, these fish can be more prone to diseases, get ill, and ultimately die.


Discus belongs to the Cichlid family and is further divided into three subfamilies. Two of these species i.e. Symphysodon Aequifasciatus and Symphysodon Discus have been discovered a long time ago, whereas the third one i.e. Symphysodon Haraldi has been discovered just recently.

Nowadays, it is really difficult to find the wildlife species of Discus Fish as they are less in number as compared to the Discus obtained by selective breeding. Selectively bred Discus are a lot different from the wildlife species in terms of physical appearance.

Discus is one of the most demanding freshwater tropical fish. It needs stable water parameters, a spacious aquarium, great quality food and the fish itself is not one of the cheap ones either. Let’s delve a little deeper and explore everything about this majestic creature, its care, and survival requirements.

Appearance and Size

As the name indicates, Discus is a large fish with a disc-shaped body. This is one of the Cichlid species with the most flattened body shape, just like a disc. It is almost impossible to pinpoint a particular color of Discus as there are a lot of species with varying hues and shades in their bodies.

Some common colors of Discus fish include:

  • Green
  • Red
  • Blue
  • Brown

The huge range of colors in Discus is mostly because of the selective breeding in them.

Where this selective breeding has created a great number of beautifully colored Discus fish, it also has reduced immunity in them. This is the main reason why these fish are more prone to diseases and therefore require a great deal of attention and care.

As far as the size of Discus is concerned, they can grow up to 20-25cm or 8-10 inches in diameter. They can live for almost 10–15 years if they get favorable conditions and care. Within 2-2.5 years, they can reach their maturity and grow to their full size.

Difficulties in Keeping Discus Fish

Due to the intense amount of care and attention required, Discus is definitely a fish for experienced aquarists. Beginners should usually start their fishkeeping journey with hardy fish such as Platies, Guppies, Swordtails etc. that require considerably less care and attention.

To be perfectly clear, Discus are so much demanding that sometimes it even gets challenging for the experts to take care of them. They need stable water parameters, quality feeding, a spacious tank, and an incredibly good filtration system.

Sudden changes in water parameters, quick relocation, improper water care etc. are all factors that can cause stress among your Discus fish and stimulate the development of diseases in them.

Ideal Parameters for Keeping Your Discus Happy

To keep Discus fish happy and healthy, you need to take into account a number of factors. First and foremost, the size of your tank is extremely important. Discus are relatively large fish and therefore need a spacious aquarium.

To keep a group of 5-6 Discus fish, you need an aquarium with the capacity of almost 50-55 gallons of water. In case you want to keep more fish with them, the capacity of your aquarium needs to be much more than that. Discus are quite wide and tall fish, therefore, the aquarium should be long and high as well.

Following are the most important water parameters that you should take care of, in order to provide an ideal habitat to your Discus fish.


The optimum water temperature for Discus is around 82̊F-83̊F or 28̊C-31̊C. As the temperature gets higher, the level of dissolved oxygen in water drops down and therefore limits the number of fish that can be housed in the aquarium.

It is the main reason why it is so difficult to choose tankmates for Discus. So, when you want to add more fish with them, you should go for the ones that can survive in this situation.


Discus fish thrives well when the pH level of water falls within the range of 6-7. Ideal pH level for Discus is around 6.5. If this value increases or decreases, it may cause stress among them. Discus can live comfortably in this pH level water as long as there is no fluctuation.

Water Hardness

Water hardness is another important factor that contributes towards the health and survival of Discus. The relative hardness of water should fall within the range of 1-8DH. This is similar to the soft water conditions of Amazon which is the home for wild Discus species.

Tank bred Discus can easily withstand higher degrees of hardness. Hard tank water can be easily softened by adding a piece of Driftwood in the aquarium.

Nitrite Concentration

Nitrite is extremely poisonous for any kind of freshwater tropical fish. Same goes for Discus. The concentration of Nitrite in your aquarium should be 0ppm.

Ammonia Concentration

Just like Nitrite, Ammonia is also deadly for Discus and its concentration should also be 0ppm in your aquarium. Due to a weak immune system, Discus can easily be prone to diseases if the Ammonia levels rise even a little bit.

You can notice loss of color and intense breathing of Discus if ammonia is present in your tank water. You would have to change the water immediately or your Discus might die.

Nitrate Concentration

Nitrates are not as deadly as compared to Nitrites and Ammonia, but their level should also be kept low. Nitrate levels under 20ppm are harmless for Discus. You can easily reduce the elevated Nitrate concentration by adding aquatic plants and removing the decaying matter.

Regular Care

If you have read this article till now, you must have gotten the idea why Discus are not an easy fish to keep as they require specific care and water conditions that inexperienced fish keepers cannot provide. Therefore, Discus fish should only be kept by those who are passionate enough to learn how to properly take care of them.

To maintain an ideal pH level for Discus, you should keep them in a planted tank with carbon dioxide injections. This will keep the pH level within the normal range i.e. 6.5, allowing you to avoid unnecessary stress in your aquarium.

Another great way to maintain healthy water conditions for Discus is the use of bare bottom tanks. Although this type of tank may not be visually appealing, it makes it easier to clean the debris and feces of the fish that may contaminate the water otherwise.

Following are some of the important points that you can keep in your Discus care checklist:

  • Keep your aquarium water clean
  • Keep your aquarium in a quiet place
  • Maintain the water temperature within the range of 28̊C-31̊C
  • Your aquarium should have enough foliage to give a feeling of natural habitat to your Discus
  • Feed the right food, at the right time, and in the right quantity
  • Use a high-quality filtration system
  • Maintain pH levels within 6 – 7
  • Change the water on a weekly basis

Normal Behavior of Discus

If you ever get a chance to notice the behavior of Discus, you will realize that they don’t really compete for mates. They are really social and friendly fish and can get along with a number of fish species.

Despite that, a few exceptions always exist.

The peaceful behaviour of Discus may change when they reach maturity and start to seek their breeding partners. At that time, you can observe a lot of aggressive behavior among the males and they may even start to bully other males in order to win the breeding partner.

If you are a breeder, then this information can be really useful for you. Ensure that you can keep a number of same age Discus in your aquarium in order to maintain equality among them.

Feeding Discus Fish

The “king” Discus likes to be fed in the middle of the aquarium and doesn’t like the food floating at the surface of the water near the corners. You can feed bloodworms, beef hearts, pellets, and flakes to your Discus.

You can feed a variety of stuff to your Discus but, due to their carnivorous nature, they usually like bloodworms and beef hearts. Pellets and flakes are really good for them too as they provide them with vitamins and minerals.

If you want to achieve the best coloration in your Discus, you can feed them with a combination of processed and frozen live foods. The best processed food is granules as is really easy to feed them in the middle of the tank.

When feeding black worms to your Discus, you should be extremely careful as they may contain parasites in them that can be harmful to the health of Discus fish.

Also, when feeding beef heart to the Discus, you should take special care as it may contaminate the tank and therefore, increase the poisonous chemicals in the water. Be sure to clean up the water really well and use an efficient filtration system.

Possible Diseases

All tropical freshwater fish are delicate and can easily catch diseases and Discus are one of those fish that have the weakest immune system among them. Therefore, chances of Discus getting sick are a lot higher as compared to the other fish.

A carefully maintained aquarium can never be a center of diseases. Most of the diseases in fish arise just because of the poor water conditions in the aquarium. Just a little change in the ideal parameters of water can cause a lot of stress and diseases in your Discus fish.

Discus fish may be prone to a number of diseases due to unhygienic conditions. Some of these diseases include:

  • Imbalance
  • Swollen eyes and abdomen
  • Fin Rot
  • Ick
  • Leeches on the body
  • Flukes
  • Bacterial infections and ulcers
  • Tail Rot
  • Parasitic infection causing holes in the body with pus
  • Cloudy eyes
  • White stringy feces
  • Plague

A lot of the above-mentioned diseases can be cured by cleaning and changing the water regularly. This can reduce the biomass in the water and can free it from the toxic substances. You can also use some common medicines like Octozin and Interpet Anti-Internal Bacteria etc. depending on the type of disease.

Also, if you regularly deworm your Discus fish, you can keep them from getting any of the diseases mentioned above. The easiest way to deworm your fish is by using the medicine named Metronidazole commonly known as Flagyl. This medicine has antibiotic properties and can kill a number of bacteria and parasites.

It is extremely important to note that you should never self-medicate your fish. Always consult a vet before medicating your fish.

Best Tank Mates for Discus

Because Discus fish live in relatively warm water and conditions that are not really favorable to other tropical fish, finding a tank mate for them can be a really challenging task.

If you are planning to keep only a few of these fish in your aquarium, chances are that they may feel lonely or bored.

Some of the species that go well with Discus are:

  • Bettas
  • Angel Fish
  • Guppies
  • Cory Catfish
  • Loaches

Gender Differences in Discus

Finding out the gender of Discus fish is not easy at all. The only way you can know the difference between the male and female Discus is by waiting for the spawning period. Some of the expert aquarists can tell the difference between male and female by the shape of their heads.

According to the experienced aquarists, male Discus has a thick forehead and also has fuller lips. During the spawning period, it is quite easy to distinguish male from females as female Discus has a larger breeding tube between its anal fin and the anus.


In order to provide a perfect environment for breeding, you must take care of the water parameters such as temperature and pH levels. Once the conditions are favourable, Discus can do the rest of the work on their own.

To increase the population of your Discus, you need to find a healthy pair of Discus from a reputed breeder. You can also get a young pair of Discus so that when they reach maturity, they can breed and give you a whole new generation.

It should also be kept in mind that mature and ready-to-breed male Discus can show aggression towards other males in the race of winning the female. So, you should keep an eye on the breeding pair. It is a good idea to keep them in the separate tank.

Taking Care of Discus Fry

In order to keep the Discus fish comfortable during the spawning period, you can provide a spawning medium to them. This medium should be kept in the middle of the aquarium so that the fish can easily lay eggs there after cleaning it.

Discus pair mates and lays eggs every week for almost 15 weeks. If everything goes well and the mating pair gets favorable conditions, they can stay with each other for their whole life and produce more offspring.

Discus eggs are usually small and opaque spheres that stick together in the form of a cone. Parent fish continuously fan the eggs for the proper ventilation that also keeps them safe from the parasites. Within 48 hours of laying, eggs start to hatch. The fry are usually ready to swim two days after birth. Until that time, baby Discus feed on a secretion released by their mother so there is no need to feed them in the first 48 hours after their birth.

In order to prevent the aggression among the parents and the fry, you can separate them after the two-day period. You can feed commercial food to them. Once they grow up to 2 inches in diameter, you can sell them or keep them if you want.

Related Questions

What are the best tankmates for Discus? Usually, it is hard to find a good tank mate for Discus as their survival requirements are different from other fish. However, tropical fish like Bettas, Angel Fish, Guppies, Cory Catfish, and Loaches can give good company to them.

How long can Discus fish survive without eating? Adult Discus can survive for more than a couple of weeks without eating. But, if you want them to grow well and healthy, you have to feed them at least three times a day.

How many Discus fish can be kept together? Discus are relatively large fish with territorial problems. Therefore, you will need a spacious aquarium for them. You can follow a general rule of thumb in this case; you can have 1 Discus for every 10 gallons of water. So, if you want to keep 5 Discus fish together, you need an aquarium with at least 50-gallon water capacity.


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