Everything you know about Discus

The king of the aquarium, Discus fish are one of the most beautiful freshwater fish available for the home aquarium. Peaceful, but larger than most tropical fish, these fish light up the room they are in.

The king of the aquarium, Discus fish are one of the most beautiful freshwater fish available for the home aquarium. Peaceful, but larger than most tropical fish, these fish light up the room they are in. The beautiful colors of this fish change based on stress levels, age, diet, and the tank’s conditions. They are treasured in the aquarium trade for their bright appearance and shoaling behavior.

Discus Fish Overview

Recent research suggests are five species of Discus, though there is some debate around this. In the aquarium hobby, there are two species that are commonly available: Symphysodon aequifasciatus and Symphysodon Discus. There are many color variations available thanks to selective breeding, and interestingly it can take up to 6 years for them to reach their best colors. They can live up to 15 years, but most live for around 10 years. You will find they are available at most aquatic stores, but rarer colors will have to be ordered through your local store or on the internet. You should expect to pay anywhere from $25 to several hundred dollars, depending on the species purchased. Most will cost around $40 per fish. They are often bred in southern Asia, but they originate from the Amazon where they populate flood plains and cling to breaks in the water flow in large schools.

Typical Behavior

Discus fish are very peaceful, avoiding conflict through escape and intimidation. In most tanks, they are one of the largest and brightest fish. They are a schooling fish, and in large groups can create a wall of patterns across the tank. Like all cichlids, there can be some competition in the shoal and a pecking order will be established. This means smaller fish will need to be monitored to make sure they are able to eat. They tend to stay in the mid-levels but will rise to the top and dip to the bottom to forage; so they can easily dominate all levels of the tank. They do prefer to be free-swimming but need the option to be close to cover such as large driftwood or plants in the tank.

Appearance of Discus Fish

Discus fish are named after their disc shape appearance – some variations are more triangular or round than others, but all are thin and flat looking. They have rounded dorsal and anal fins that add to their overall body shape, as well as pronounced pelvic and caudal fins. The body can be 8-10 inches long, making them a large fish for home aquariums. Their popularity comes from their intense colors that can have greens, bright blues, reds, browns, yellows. They are much brighter when bred in captivity compared to their wild counterparts. The coloring comes together in vertical and horizontal stripes that cover fins as well as their body. They become more pronounced and will flare when they feel threatened, which is beautiful but should be avoided as they are sensitive to stress. Their eyes come in a variety of colors too, with red being highly prized – red eyes are not a sign of health despite this myth being spread frequently.

Discus Fish Types

The different types of Discus are based on their colorations. Varieties such as Giant Flora and Red Alenquer Discus boast light blues and deep reds, while Albino Platinum Discus are all white with red eyes that seem to almost glow. One of the most common types is a checkerboard Discus fish, that has a mottled turquoise splashed over a deep red base. There are so many different types, it is worth your time to create a shoal that has the colors you like the most.

Discus Fish Habitat and Tank Requirements

Discus originates from the flood plains of the Amazon, where a ‘flood pulse’ can change the level of water by meters in-depth as it rises along a shallow flood plain.

This pulse provides much more space for growth, breeding and best of all, feeding.

They are found in crevices and breaks in the water flow, such as small inlets or among fallen trees, where their wide body is protected from the current. These areas are shaded, and the riverbed is soft sediment. The wild conditions of the Discus fish can be replicated in the home aquarium, however, it can be challenging for beginner hobbyists.

Discus (Fish) Tank Conditions

These fish require higher temperatures than most fish 82-88°F. Keeping this warmer temperature will reduce the chance of illness and deaths, it can be maintained using a good quality heater. Amazonian water is soft and slightly acidic, with a pH between 6 and 7. Check before purchasing your fish what pH and temperature they have been raised in to prevent drastic changes that could be fatal. The water in your aquarium needs to be de-chlorinated and treated with formulas that neutralize your tap water. The flow should be weak, this can be broken using a spray bar or by using driftwood or ornaments. Vertical wood can also be used to break the water flow, just make sure that these pieces of wood can’t injure the side of the Discus as it swims past. They prefer soft to medium sediment, as they often search for food on the substrate and larger pieces could injure them as they forage. Plants such as the Amazon Sword Plant or Dwarf Hairgrass are easy to add to your tank and provide oxygen to your fish. Plants also act as a nutrient sink, meaning drops in water quality are rarer.

What Size Tank Do Discus Need?

As these fish need to be in schools of at least 5, a 50 gallon tank is the smallest tank they will thrive in. They prefer larger tanks, and upwards of 100 gallons means there will be less drastic changes in water conditions and they will have the space they desire. One Discus fish per 7 gallons is ideal.

Discus Tank Mates

Discus can often be shy, but this can be helped by surrounding them with a couple of other fish (known as dither fish) that show them they are not in danger. Fish that come from the same warm Amazon waters are a great place to start, and shoaling Tetras can look amazing. These include Neon Tetras, Rummy-nose Tetras, and Ember Tetras. They are beautiful and easy to care for. Other great fish to pair them with are Gouramis, Bolivian Rams and Pencil fish. Marbled or Neon Hatchet fish are great fish to pair with them, because hatchet fish occupy the highest level of the tank, just make sure your lid is tightly fitted. Almost all Corydoras would pair excellently with these fish, however, they often require colder waters. Sterbai Cory Catfish is the best type of catfish to include because they live in warmer waters while occupying a different level of the tank and being extremely peaceful. These fish can’t be paired with aggressive fish, and some fish try to eat the Discus’ mucus coat which wounds them. Angelfish are sometimes no trouble, whilst other times they bully them and out-compete them for the limited supply of food. It really comes down to the individual temperaments of each of the fish so if you want to keep these fish together, do it with caution. They are also compatible with any of the larger species of snail and shrimp but watch that they are not small enough to be eaten or damaged.

Can You Keep Discus Fish Together?

Discus should be kept together, and those of different varieties will also school together meaning you can have great color variations. A minimum of 5 is recommended, but more will look better and create a sturdier group.

Discus Fish Food

Discus is omnivores, and in the wild, they primarily eat green plant matter such as algae or fallen food. A third of their diet also comes from arthropods, such as insects or crustaceans, and invertebrates such as copepods and amphipods. For the best coloration, a variety of foods should be given to them. Different kinds of flake food such as spirulina and tropical fish flakes, combined with algae or shrimp pellets, can make up the vegetable part of their diet. Live food such as blood worm, mosquito larvae, and brine shrimp is good for them and can encourage bright colors to show. Beef heart, while not natural, is commonly fed and does no harm. They will need feeding every day, and only what they eat in a 3-5 minute window. Any excess food should be cleared up after 5 minutes, as excess food can lead to health issues or bad quality water. As they have a pecking order, you should also watch your fish make sure that all of them are able to eat and aren’t being blocked by larger tank mates.

If this happens consistently, you can put feed at either side of the tank.

Discus Fish Care

Breeding fish can be a challenge, but breeding Discus is a real challenge. They are very difficult to breed however, this makes them very rewarding too. They have very specific requirements for breeding, and all the parameters previously mentioned (in the tank setup section) must be perfectly maintained. It is advised to use a spawning cone, which provides the ideal place for them to lay their eggs, and then you can place a tube of wire over the eggs to stop them from being eaten. Some breeders then separate the female as she is more likely to cannibalize her fry, and the male will rear the fry on his own. The fry hatch after three days, and in another three days they will be independent swimmers, feeding on mucus produced by their parents.

Are Discus Fish Right For Your Aquarium? (Summary)

Although Discus fish are challenging, they are not as daunting as they seem, and the value gained from their beautiful appearance makes them more than worth it. They can help to make your larger tank something to show off. Make sure to monitor the water temperature/quality closely and you will be rewarded with beautiful colorful fish. Are you inspired to try your hand at keeping the king of the aquarium? Let us know in the comments below.