Discus
The Discus (Symphysodon species) is the "king of the aquarium" - a disc-shaped, brilliantly coloured cichlid considered one of the most beautiful freshwater fish.
Overview
The Discus (Symphysodon species) is the "king of the aquarium" - a disc-shaped, brilliantly coloured cichlid considered one of the most beautiful freshwater fish. Discus are also one of the most challenging - requiring very soft, very warm, immaculately clean water and large groups for proper behaviour.
Natural History
Native to the Amazon basin in slow-moving blackwater rivers. Three species (S. aequifasciatus, S. discus, S. tarzoo) plus many captive-bred strains.
Appearance
Adults 15-20 cm body length, disc-shaped. Brilliant patterns and colours: red turquoise, blue diamond, pigeon blood, snake skin, leopard, marlboro, and dozens more.
Temperament & Tankmates
Peaceful cichlids. Best in groups of 6+ - solo Discus are stressed and short-lived. Pairs and trios often produce dominance issues; large groups are most stable.
Tankmates: only fish that tolerate the high temperatures and soft water Discus require. Cardinal Tetras (often), Sterbai Corydoras, peaceful South American fish.
Tank Size & Setup
Minimum: 200 L (55 gallon) for a group of 4-6. Tall tank preferred.
Heavy filtration, very clean water, large weekly water changes (50%+).
Water Parameters
- Temperature: 28-30°C (warmer than typical tropical).
- pH: 5.5-7.0.
- Very soft water.
Diet
Carnivore. Frozen bloodworms, brine shrimp, beefheart (controversial), quality Discus pellets, blackworms. Feed 2-3 times daily; juveniles more often.
Health & Lifespan
10-15 years.
Common concerns:
- Sensitive to water quality - Discus are the fish that demand "perfect" water.
- Internal parasites.
- Hexamita.
- Bacterial infections.
Pros & Cons
Pros: stunning appearance, intelligent, long-lived, social. Cons: demanding water quality, expensive setup, sensitive to disease, not for beginners.
Discus - frequently asked questions
Are Discus for beginners?
No. Experienced fishkeepers who can maintain soft warm water with rigorous cleaning.
How big do they get?
15-20 cm body diameter.
How long do they live?
10-15 years with careful care.
Cost?
Quality Discus often €40-€200+ per fish. Setup is substantial.
Are they worth the trouble?
For dedicated keepers, yes. Discus are widely considered the pinnacle of freshwater fishkeeping.
🧠 Test yourself: guess the fish
Three clues from our quiz bank, each about another of our fish. Can you name them?
Clue 1.Fancy varieties of this fish include bubble-eye and telescope-eye types bred for unusual looks.
It's the Goldfish - read the full profile →
Clue 2.This peaceful armored aquarium fish gulps air from the surface and breathes part of it through its gut.
It's the Corydoras Catfish - read the full profile →
Clue 3.A laterally compressed cichlid with vertical dark stripes, it forms monogamous pairs and guards its eggs on a flat leaf or surface.
It's the Angelfish - read the full profile →