Discus fish are one of the most beautiful freshwater fish available for the home aquarium. This is due to their distinctive shape, behavior, and bright colors and patterns. Discus are cichlids and by nature cichlids prove to be hardy fish and for the most part Discus are very hardy. Discus fish are very peaceful, avoiding conflict through escape and intimidation. In most tanks, they are one of the largest and brightest fish.
Symphysodon aequifasciatus and Symphysodon Discus colloquially known as discus and are named after their disc shape appearance They are a genus of cichlids native to the “Blackwater” regions of the Amazon river basin (Rio Negro) in South America. These area are subject to ‘flood pulses’ can change the level of water by 10 meters in-depth as it rises along a shallow flood plain. These pulses provides much more space for growth, breeding and best of all, feeding. The Rio Negro river is known for it’s “black water” that is dark from tannic acids and very low in ph because of all the rotting vegetation these waters contains. The water is typically soft and slightly acidic, with a pH between 6 and 7.
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.
There is no clear sexual dimorphism for this fish, but males may reach a larger size than females.
Discus typically reach up to 12–15 cm in length, but captives have been claimed to reach 23 cm. Adults generally weigh 150–250 g. So you will need a large tank! As these fish need to be in schools of at least 5, a 200 litre tank is the smallest tank they will thrive in. They prefer larger tanks, and upwards of 400 litres means there will be less drastic changes in water conditions and they will have the space they desire. One Discus fish per 30 litres is ideal.
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. 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.
Some suitable aquarium mates include cardinal tetras, neons, emperor and rummynose tetras as well as clown loaches and dwarf cichlids, such as rams and Apistogramma species. All of these fish tolerate the high temperatures and low pH/hardness required by discus. 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.
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.
These fish can’t be paired with aggressive fish, and some fish try to eat the Discus’ mucus coat which wounds them.
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/frozen food such as blood worm and brine shrimp are good for them and can encourage bright colors to show.
Notoriously tricky to care for, but so rewarding when kept correctly, Discus fish are the pride and joy of those that keep them. They require higher temperatures than most fish at 27-31°C and a slightly acidic pH. Keeping this warmer temperature and pH will reduce the chance of illness and deaths, so a good quality heater is recommended.
Discus fish are sensitive to water parameter changes. If they are unable to balance, leaning on the driftwood or against the side of the tank, then it could indicate a nitrite spike. These fish need weekly full tank cleans, with water changes of 25% and the sediment cleaned using a gravel vacuum to remove excess food.
Parasite infections can also cause the fish to scratch their sides on ornaments or on the sediment. Reddened areas may also show up, with rapid breathing.
|Adult Size:||12–15 cm|
|Aquarist Experience Level:||Intermediate/advanced due to large size and water conditions|
|Minimum Tank Size:||200 litres, +30 litres per additional|
|Temperament:||Peaceful, often compatible|
|Tank Level:||Mid dweller|
|Water Flow:||Slow to Moderate|
|Temperature:||27-31°C (warmer than typical)|
|pH:||6 – 7|
|Hardness:||up to 15 dGH (soft)|