Discus Fish Care: Water, Tank Setup and Feeding

Discus (genus Symphysodon) are disc-shaped cichlids from the Amazon basin, often called the kings of the freshwater aquarium for their colour and their demands. Adults grow to about 6-8 inches across, live 10-15 years, and need water warmer than almost any other community fish: 82-86°F, soft and slightly acidic, and above all extremely clean. Keep them in groups of 5 or more in a tall tank of 75 gallons or more.

Photo: Patrick Farrelly - Wikimedia Commons, Public domain

Parameter	Value
Genus	Symphysodon (family Cichlidae)
Origin	Amazon basin, South America
Adult size	6-8 in (15-20 cm) across
Lifespan	10-15 years often reported
Temperature	82-86°F (28-30°C); range 79-86°F
pH	6.0-7.0
Hardness	Soft water preferred
Group size	5-6 or more
Minimum tank	About 67 gallons for a pair; 75+ gallons for a group; tall rather than long

Water Changes Are the Real Discus Secret

Discus keepers argue about almost everything except this: discus need very low nitrate and very stable water. Many breeders change 30-50% or more of the water several times a week, especially for juveniles. Match temperature closely, dechlorinate every change, and avoid big swings in pH. Most discus problems, from dark colour to refusing food, trace back to water quality.

Setting Up a Discus Tank

• Tall tank: discus are high-bodied, so height matters as much as length.
• Calm water: gentle flow, strong but quiet filtration.
• Bare bottom or sand: many keepers use bare-bottom tanks for easy cleaning; planted tanks work if plants tolerate 82°F or more.
• Quiet location: away from doors and heavy traffic, since discus startle easily.

Feeding

Discus are slow, picky eaters. Offer high-protein foods such as quality discus pellets or granules, frozen bloodworms, brine shrimp and beefheart mixes, two or three times a day for adults and more often for juveniles. Remove uneaten food quickly: leftovers are the fastest way to pollute their water.

Choosing Healthy Discus

Buy discus that are already 3-4 inches or more, eat in front of you, swim with fins open and show even colour. Avoid fish with dark colour, pinched foreheads, white stringy waste or clamped fins. Quarantine new arrivals before adding them to an established group.

Tank Mates

Discus do best with calm fish that tolerate heat: cardinal tetras (see cardinal tetra care), sterbai corydoras, rummy-nose tetras and bristlenose plecos. Avoid fast, boisterous eaters, fin-nippers and fish that need cooler water. Freshwater angelfish share their range, but many keepers avoid the mix because of disease risk and competition for food.

Related Guides

• Freshwater angelfish
• Cardinal tetra
• Corydoras catfish