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Discus

Symphysodon aequifasciatus

Freshwater South America Usually captive bred

A round, flat cichlid that needs warm water, 28 to 31 C, and scrupulously clean water. It is slow to feed and can be outcompeted by faster fish. Keep in a group of five or more.

Also called: Blue discus, Brown Discus, Green discus.

15 cm adult length, drawn to scale. round body.

Try it in the planner Opens a tank sized to its minimum with 5 fish added.

What it needs

ItemValueBecause
Adult length 15 cm Used for the Space check: the tank must be long enough for the fish to turn round.
Smallest tank 250 L, at least 120 cm long estimated The least water and floor length this species is kept in for good, as a single fish or smallest group.
Extra water per added fish 40 L estimated What each further fish adds once the minimum is met.
Waste load Class 4 of 5 estimated How much waste an adult makes against its size. Feeds the Load check.
Temperature 28 to 31 C Stock sharing a tank need overlapping ranges.
pH 5.5 to 6.8 Compared with tankmates in the Water check.
Hardness GH 1 to 8, KH 1 to 4 Degrees of general and carbonate hardness.
Flow Low Low-flow fish are stressed in a strong current.
Light Dim Matched to the lighting class on the needs sheet.
Group size At least 5, ideally 6 Kept alone or in small numbers it hides, fades or turns on tankmates.
Temperament Peaceful Territorial: weak.
Swims in Middle water Fish that use different levels share a tank more easily.
Lifespan About 10 years A fish is a long commitment.
Experience Experienced keepers only A guide to how forgiving the species is of mistakes.

Tags marked estimated are judged from the size and habits of the species rather than measured, so treat them as a sensible default.

Diet and tank layout

Discus is an carnivore that swims in the middle of the tank. It is safe with plants. Give it some cover.

Tankmates

Works with

No close matches in the data. Check the pair tool.

Depends

Avoid

Compare any two fish on the compatibility page, or print the equipment for a stock on the needs sheet. How this is worked out: the method.