Discus care guide
Also called: Discus fish, Pompadour fish, Blue discus, Heckel discus, King of the aquarium
Discus are round, brightly colored Amazon cichlids that grow about 15 cm (6 in) across. They are calm, shy and stunning in a group, but they need very warm, soft, spotless water and frequent large water changes.
Discus need a tank of at least 75 gallons (284 L), a group of 5 or more, and water at 28–30°C (82–86°F) with a pH of 6–7. They grow to about 15 cm (5.9 in) and are peaceful.
Plan a tank with discusSee all tank mates
Discus quick facts
| Scientific name | Symphysodon spp. |
|---|---|
| Family | Cichlidae |
| Origin | Amazon basin, South America (nearly all sold are captive-bred color strains) |
| Adult size | 15 cm (5.9 in) |
| Minimum tank | 75 gallons (284 L), at least 120 cm (47 in) long |
| Temperature | 28–30°C (82–86°F) |
| pH | 6–7 |
| Hardness (GH) | 1–8 dGH |
| Group size | 5 or more (group) |
| Temperament | Peaceful |
| Swims at | Middle |
| Diet | Omnivore |
| Care level | Hard |
| Lifespan | 10–15 years |
| Safe with shrimp? | No, eats shrimp |
| Safe with plants? | Yes |
Tank setup
Plan on a 75-gallon (284 L) tank at least 120 cm (48 in) long for a group of five or six adults. A tall tank suits their deep, round bodies. Keep decor simple, with driftwood and some plants for cover, and avoid strong currents.
How many discus in a tank?
The smallest common tank that suits discus is a 75 gallon. Here is roughly how many fit in each size when they are the only fish, based on adult size and waste output. Leave room if you want tank mates.
| Tank | Discus (alone) |
|---|---|
| 3 gallon | Too small |
| 5 gallon | Too small |
| 10 gallon | Too small |
| 15 gallon | Too small |
| 20 gallon | Too small |
| 20 gallon long | Too small |
| 29 gallon | Too small |
| 40 gallon | Too small |
| 55 gallon | Too small |
| 75 gallon | 5–10 |
| 125 gallon | 5–16 |
What you need for discus
Sized for a 75 gallon tank, the smallest common size that suits a group of 5 discus. For a different tank or a mix of fish, use the stocking calculator for a list sized to your plan.
Tank and equipment
- 75 gallon aquarium (tank or kit) (opens Amazon in a new tab)Bigger tanks are more stable and easier for beginners. How to choose
- Aquarium stand for 75 gallons (opens Amazon in a new tab)The water alone weighs about 626 lb (284 kg), before glass, gravel and rock. How to choose
- 2 adjustable heaters, 200 W each (opens Amazon in a new tab)Holds about 84 °F (29 °C) in a room at 65 °F (18 °C). Two heaters keep the tank warm if one fails. How to choose
- Aquarium thermometer (opens Amazon in a new tab)Check it daily: heaters can fail stuck on or off. How to choose
- Hang-on-back filter rated 300–450 GPH (opens Amazon in a new tab)Community tank: 4–6 times the tank volume per hour. How to choose
- About 100 lb of aquarium gravel (opens Amazon in a new tab)Enough for a layer about 2 in (5 cm) deep. Smooth gravel suits most community fish. How to choose
- Water conditioner (dechlorinator) (opens Amazon in a new tab)Removes chlorine and chloramine from tap water. Seachem Prime is a popular, concentrated choice. How to choose
- Liquid test kit (ammonia, nitrite, nitrate, pH) (opens Amazon in a new tab)Liquid kits are more accurate than strips. The API Freshwater Master Test Kit is the common choice. How to choose
- Gravel vacuum (siphon) (opens Amazon in a new tab)Cleans the gravel and does the water change in one go. How to choose
- LED aquarium light, about 48 in long (opens Amazon in a new tab)Match the light to the tank length. Basic LEDs grow easy plants. How to choose
Food and extras for discus
- Cichlid pellets (opens Amazon in a new tab)Larger pellets for cichlids and other big fish.
- Indian almond leaves (opens Amazon in a new tab)Release tannins that soft-water fish like bettas and rams enjoy.
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Water parameters
Hold the temperature at 28–30 °C (82–86 °F), with pH 6.0–7.0 and soft water of 1–8 dGH. Captive-bred discus cope with slightly harder water, but they never cope with dirty water. Most keepers change a large share of the water at least weekly and keep nitrate under about 20 ppm.
Best tank mates for discus
These popular species share discus' water needs and temperament. See the full list of 3 good matches.
Avoid keeping discus with
- Bristlenose pleco: They need different temperatures: Discus 28–30°C (82–86°F), bristlenose pleco 22–26°C (72–79°F).
- Bronze corydoras: They need different temperatures: Discus 28–30°C (82–86°F), bronze corydoras 21–26°C (70–79°F).
- Cherry shrimp: They need different temperatures: Discus 28–30°C (82–86°F), cherry shrimp 20–27°C (68–81°F).
- Common goldfish: They need different temperatures: Discus 28–30°C (82–86°F), common goldfish 15–22°C (59–72°F).
- Fancy goldfish: They need different temperatures: Discus 28–30°C (82–86°F), fancy goldfish 18–23°C (64–73°F).
- Guppy: They need different temperatures: Discus 28–30°C (82–86°F), guppy 22–27°C (72–81°F).
Feeding
Discus are slow, picky eaters with small mouths. Feed discus granules or small pellets plus frozen brine shrimp, blackworms and bloodworm, but don't let bloodworm become the only food they accept. Give small meals two or three times a day and remove leftovers quickly.
Behavior
They are peaceful toward other fish but shy, and they hide or turn dark when stressed or beaten to food. Within a group they form a pecking order. Maturing males and newly formed pairs can turn on the others, so a group with more females than males works best, and one bully may need to be moved out. Keep them only with calm fish that like the same heat, such as cardinal tetras and sterbai corydoras.
Breeding
Breeding discus takes soft, acidic water and a lot of work. A bonded pair lays eggs on a cone, slate or broad leaf and guards them together. Once they swim, the fry feed on a special mucus on their parents' skin. Breeders usually add baby brine shrimp after about a week, while the fry keep grazing on the parents for a few more weeks.
Tips from experienced keepers
- Buy fish of the same size from one healthy batch, and quarantine any newcomers for several weeks.
- Check the heater daily. A sudden temperature drop stresses discus quickly.
- Choose slow, peaceful tank mates so the discus are not beaten to food.
- Do big, regular water changes with dechlorinated water matched to tank temperature.
- Avoid keeping them with angelfish, which compete hard for food and can bring in disease.
Frequently asked questions
How many discus should be kept together?
Keep at least five, and six or more is better. In pairs or trios the strongest fish often bullies the rest.
Are discus good for beginners?
Usually not. They need very warm, soft, clean water and frequent large water changes, so most people start with hardier fish first.
What temperature do discus need?
About 28–30 °C (82–86 °F). That is warmer than most community fish like, so pick tank mates that enjoy the heat.
Sources
We checked these references when writing this page. Values are for healthy long-term keeping, not survival limits. Last reviewed 2026-10-13. See our editorial policy.