Discus Fish: Everything You Need To Know Guide

Discus (Symphysodon) is one of the most beautiful freshwater fish available in the hobby. Their unique appearance and coloration made them one of the most sought-after freshwater aquarium fish. After years of line breeding these fish, we now have many different color patterns available in the market.

In this article, You will find all the information you need about discus fish a.k.a King of the aquarium!

Discus fish Overview

Discus is a freshwater fish belonging to the Cichlidae family native to the Amazon River in South America. Discus are popular aquarium fish for their unique disk-shaped flat body.

Like all cichlids, Discus will prey upon small fish and invertebrates in the tank and will fight over territory. They tend to be compatible with most small predatory and non-predatory fish. This makes them a great fish for community tanks and will make a great addition to any aquarium. 

However, they are extremely fussy and difficult fish to keep. Keeping these fish healthy and alive is a tedious job and you will need to put in a lot of time and work into it. Following all the points we mentioned here in this article will help you keep this fish healthy and alive for years to come. 

In the wild, Discus fish are found in slow-moving streams and rivers where water is warm and slightly acidic. The fish’s natural habitat is filled with driftwood, fallen trees, and live plants that they can scavenge for small creatures to prey on. 

In Aquarium, you will need to add driftwood, plants, and rocks to mimic their natural habitat. This will make them feel safe and calm them down. 


Yellow Discus Fish
Yellow Discus

This looks very similar to a disc which is why they named this fish Discus Fish (Circular Fish). They have compressed but round bodies with fins that are not too long, which makes these fish very beautiful. In the wild, their body shape helps them to hide, behind roots and plants, from predatory larger fish. Discus are semi-peaceful fish with occasional aggressive tendencies, especially in the breeding season.

The wild varieties are usually striped with dull colors so they can camouflage in rivers. The captive-bred varieties are line bred to create different colors and more beautiful patterns. 

These fish are very vulnerable to stress and will lose their color and vibrancy when they are under stress. They might also lose color when water parameters, tank setup, or food is not in their favor. This is more visible in wild-caught Discus that are not well adapted to aquarium environments. 

Discus size:

Discus fish will grow to 5-10 inches in diameters (including the fins). They will only grow to 10 inches when the food is right and the tank is big enough. Most discus fish kept in aquariums will only grow to an average of 6 inches.

Female Discus has smaller bodies compared to males.


Under the right conditions, Discus will live for about 10-15 years. A bad diet, low water quality, and stress will reduce the life expectancy of this beautiful fish. 

Behavior & Temperament

Discus are semi-aggressive active fish that don’t mind living with other small cichlids or other small fish types. They will swim around the tank without causing any trouble for other plants or the same-size fish. These fish are more active during the day than at night.

They are omnivore fish and will eat any small fish or shrimp that fits in their mouth. They are also ambush predators and will actively hunt small fish that might not even fit in their mouths. So it’s important to not put any super small fish with these guys.

Discus are territorial and will fight with other Discus or other types of fish over territory. This behavior is more noticeable once they pair up and start to breed. To reduce territorial behaviors you should first avoid adding too many fish and move tank decoration around from time to time. 

Discus care:

Discus prefers to live in well-aerated warm water with slow water flow. You should set up your aquarium as close to what it gets in nature as possible. To make this happen, you should place lots of plants, driftwood, and rocks in your tank. These fish love warmer water. You will also need to raise the water temperature.

Discus are very sensitive fish and will not easily adapt to different water parameters. This makes them one of the hardest fish to keep. They are not beginner fish and only experienced fishkeepers should attempt to keep these guys. Most beginner fishkeepers buy these fish for their beautiful colors and patterns without thinking about the tank parameters they need to thrive. 

These fish need a diet that consists of meaty food as well as small amounts of algae and vegetables. When you provide them with clean water and a balanced diet they will grow healthier and will live longer. 

Overall, this is a sensitive fish and can not tolerate fluctuation in water parameters. You should only attempt to keep these fish if you already have experience keeping other South American cichlids like Angelfish or German Blue Ram.

Tank size:

The minimum tank size for a small group of Discus fish is 75 gallons Or more. These fish will grow very fast and need more swimming areas. The larger your aquarium is, the better environment you can create for this fish. The recommended tank size is only for a small group of 1-3 fish! To see true schooling behavior and make them feel safer you will need more fish and that means you’ll have to have a bigger aquarium.

If you have a big aquarium, you can house multiple Discus. When they live in larger groups, they show schooling behavior. Larger groups will make your fish feel safe and will reduce stress levels. This means your fish will live longer and will live a healthier life. 

However, keep in mind not to overcrowd the tank since this will cause behavioral problems and tank parameters might start to fluctuate. This will be fatal to your fish.

Red Melon Discus Fish
Red Melon Discus

Tank Setup:

They are one of the most sensitive freshwater fish but will adapt to any tank setup as long as the water parameters are in their favor. You’ll find your ‌‌Discus thrives when you mimic its natural environment where they get a lot of driftwoods, plants, rocks, and sandy substrate. 

Driftwood and rocks will provide hiding spots for the fish and make them feel safe and will reduce their stress levels. Discus are fast swimmers and might hurt themselves if there is sharp driftwood or rock in the tank. Make sure to select decorations that don’t have sharp edges.

Discus are omnivore fish but, despite being a type of “Cichlid”, they will not cause any harm to live plants. Adding live plants will provide beauty to your tank and these fish will enjoy swimming around and hiding in the plants. Plants will make your fish feel less stressed.


Discus needs clean water, so a good well-established tank is necessary. When filtration of your tank can’t keep the water in pristine conditions, your fish might face health issues. Your fish might get internal or external infections or diseases, or even die.

These fish like to have a slow current in the rank so you will need to buy a filter that will not produce a strong strong current. A canister filter is the ideal filtration system for these fish. These filters will keep the water super clean and will create just enough current in the tank.

Water Parameters:

Discus loves well-oxygenated warm and slow-moving water in the tank. You will need to raise the temperature of your tank to 84 – 86 degrees Fahrenheit. At this temperature, oxygen levels will naturally deplete. You will need an air stone bubbler to increase the dissolved oxygen levels in the water.

Avoid fluctuating parameters in the tank as constant water parameters are the key to the health of Discus. The following is the range this fish can handle.

  • Water temperature: 84°F – 86°F
  • pH levels: 6 to 7 
  • Water hardness: 8–12 GH

Discus Diseases & Prevention:

Discus are sensitive fish and will easily get sick. This is also due to the high temperatures they need to live in. When water parameters are not in their favor or they are under stress they tend to get sick. They are also susceptible to all common aquarium diseases that other fish might carry.

You will need to clean the tank regularly and keep an eye on the water parameters. Never leave any uneaten food in the tank to rot. Never add new fish to your tank without properly quarantining them. Regular water changes and good food will prevent many of the diseases aquarium fish might get. Prevention is the best cure! 

Diet and Feeding Requirements

Discus are omnivore species and will eat both plants matter and small fish or invertebrates. They will also eat algae, plant matter, fresh vegetables, and small microorganisms. Meaty foods are the main part of their diet. You should feed them with prep food, small crustaceans, and insect larvae. 

Discus prefers live foods over prepared food. You can feed your fish live foods such as bloodworms, brine shrimp, and other small live food available in pet stores. If live food is not an option, you can feed them frozen foods that are widely available in most pet stores and online.

There are also many commercially prepared foods available that are specifically made for discus. When feeding commercially prepared foods, always get multiple different types and feed your fish a mix of all. High-protein fish flakes or pellets mixed with a low amount of high-fiber plant food are a good mix to feed. 

Some discus will also eat fresh vegetables like zucchini, and cucumber. If this is the case for you, simply cut the vegetables and place them somewhere in the tank. Do not keep fresh vegetables like cucumber in the tank for more than 12 hours as they will start to decay and will make your aquarium dirty.

Gender Differences

Males and females Discus look very similar and are almost identical. Both genders are almost the same size and can have the same color and patterns. 

Females are slightly smaller and less bold than males. This is more obvious when both fish are mature and the same age. Males might also have a slightly bigger bump on their heads. 

Fish behavior is also another way to identify males and females. Mature males are usually more territorial and will swim around the female to protect her from other fish and males. When two fish are swimming closely and show signs that they are paired, then the bigger one is more likely to be a male. 

The best way to get males and females is by buying a group of small Discus and letting them grow and naturally pair with each other. When selecting your fish in the pet store, buy some of the large ones and some of the small ones. This will give you a good chance of getting an even number of males and females. 

Red Discus Fish by

Breeding And Reproduction:

Breeding Discus is very easy and can be done in an aquarium environment. Discus reaches sexual maturity at about 12 months old. Once you see your fish are paired, you will need to separate them and give them their own tank to lay eggs and raise their fry. 

Providing good high-protein foods and large water changes will trigger the fish to spawn. High protein foods will help the females to develop more eggs and breed faster.

These fish prefer to breed on slightly tilted vertical surfaces. You can create this breeding surface by purchasing a breeding cone. When a female is ready to lay her eggs, she will clean the cone and start laying eggs on it. Then the male will swim after her and fertilize the eggs she just laid. 

This process can take a few hours and they will lay about 100-500 eggs. The younger fish will lay low quantities while aged fish might lay more eggs. 

After about 4 – 5 days eggs will hatch but will stay attached to the breeding cone for a few more days. Once they are developed enough to freely swim, they will swim around their parents and will eat the mucus that their parents secrete over their bodies.

During this time you will not need to feed the fry and only feed them once they are big enough to forge for food by themselves.

In order to breed and raise Discus successfully, you will need to follow the recommendations we made in the “Care ” section of this article. And maintain it without any changes, even when doing your daily water changes. Yes, fry will need daily water changes, sometimes even more.

Discus Tank Mates

Discus are semi-aggressive fish and will fight over territory when they are in their breeding season. However, under the right conditions, they can live with any peaceful or aggressive fish of approximately the same size or smaller. 

Each Discus fish has a different personality, some are very aggressive and some are not at all. Most Wild-caught fish are very aggressive and will bully your fish to death. Captive-bred ones are calmer and can live with smaller fish in a community tank. 

Remember to set your tank parameters to what discus likes and only add fish that can handle these high-temperature conditions.

Here are some of the compatible fish:

Are Discus Fish Right for You?

If you have a smaller aquarium that is already filled with other fish then Discus are not the fish you want to bring home. That’s because these fish grow very big and need a large tank. They will also need water parameters that are not suitable for most fish. If your current fish can’t handle warm water then discus is not a fish you would want to bring home. Discus are also kept in groups so a bigger tank is always recommended. 

If you have a tank with small fish like rasbora, neon tetra, or shrimps then discus is not an ideal fish for you. Discus will prey on smaller fish and invertebrates. 

If none of the above restrictions apply to your tank and you have the time for regular maintenance, then Discus can be a great fish that you will enjoy having for years.

Yellow Discus Fish
Yellow Discus


Discus is a sensitive South American cichlid that looks spectacular and will grow large in your tank. They are not beginner fish and only experienced fish keepers should keep them. They will require a lot of maintenance and water changes. 

If you have any questions or need more help please reach out to us on social media or via our contact us page. We would love to hear from you. We answered some of the commonly asked questions about discus here: Commonly Asked Discus Questions