What size tank do discus need?
At least 74 gallons (280 liters) for a group of 5. The smallest standard tank that works is the 75 gallon. A bigger tank is always easier to keep stable. We give the size for an adult fish in a proper group, because the small fish in the shop will grow. Scientific name: Symphysodon aequifasciatus.
How many discus in each tank size?
This is how many each standard tank carries comfortably if discus are the only fish in it. Share the tank with other species and the number goes down.
| Tank | How many discus |
|---|---|
| 5 gallon | Too small |
| 10 gallon | Too small |
| 20 gallon long | Too small |
| 29 gallon | Too small |
| 40 gallon breeder | Too small |
| 55 gallon | Too small |
| 75 gallon | 5 |
| 125 gallon | up to 8 |
Check discus against your own tank and other fish
Good to know
- Advanced: needs very warm, very clean water and a group.
- Keep at least 5. Alone or in twos and threes, discus hide, stop eating well, or pick on each other.
Tank mates for discus
These animals like the same water, are a safe size, and have a temper that fits. It is a match on paper: always watch new tankmates for the first week.
Poor matches
- Betta: Their temperature ranges barely overlap: Discus likes 82–88 °F (28–31 °C), Betta likes 75–82 °F (24–28 °C).
- Guppy: They need different water: Discus likes a pH of 5.5–7, guppy likes 7–8.2.
- Neon tetra: No shared temperature: neon tetra wants it cooler than discus can take.
- Fancy goldfish: Goldfish do best with other fancy goldfish.
Questions and answers
What size tank do discus need?
At least 74 gallons (280 liters) for a group of 5. The smallest standard tank that works is the 75 gallon. A bigger tank is always easier to keep stable.
How many discus should be kept together?
At least 5. Discus are social animals and only behave naturally in a group. More is better if the tank has room.
Can discus live in a 10 gallon tank?
No. Discus needs at least 74 gallons (280 liters), and grows to 6 in (16 cm), far too long for a 20 inch tank.
What temperature do discus need?
82–88 °F (28–31 °C), with a pH of 5.5–7. In most homes that means a heater.
Can discus live with a betta?
It is not a good match. Their temperature ranges barely overlap: Discus likes 82–88 °F (28–31 °C), Betta likes 75–82 °F (24–28 °C).
More fish
- Bolivian ram
- Cockatoo dwarf cichlid
- Kribensis
- Convict cichlid
- Firemouth cichlid
- Electric blue acara
- All 81 species
Adult size, tank size and water ranges follow the mainstream care consensus (Seriously Fish species profiles and FishBase maximum lengths). Where sources differ we use the more cautious figure. Stocking numbers come from our stocking calculator.