Discus (Symphysodon)

Considered the kings of the tropical freshwater aquarium. Majestic fish that require warm, soft and very clean water. Not for beginners.

Detailed explanation

Discus are South American cichlids with an unmistakable circular shape. The colours range from natural brown (wild) to the most spectacular farmed varieties: Pigeon Blood, Turquoise, Leopard, White Diamond, Red Melon.

They require high temperatures (28-30°C), soft water (GH 2-8, KH 1-4) and slightly acidic (pH 5.5-6.8). The water quality must be impeccable: nitrates below 20 ppm, zero ammonia and nitrites. Frequent and abundant water changes (30-50% twice a week) are mandatory.

They are gregarious fish that suffer if kept in fewer than 5-6 specimens. The group establishes a hierarchy. The dominant shows the best colours, the subordinates tend to darken.

Feeding discus is a controversial topic. The traditional diet includes finely chopped beef heart (the famous "papetta"), but many modern breeders use exclusively high quality dry feed (Stendker, Sera Discus, Hikari) with excellent results. Frozen food (brine shrimp, bloodworms, mysis) is always an excellent supplement.

The ideal bottom is bare bottom (without substrate) for breeding aquariums, which facilitates cleaning. Display aquariums can have fine sand with wood and plants that tolerate high temperatures (Anubias, Echinodorus, Microsorum).

Discus are sensitive to stress. Aggressive aquarium companions, loud noises, frequent passages in front of the aquarium make them nervous and subject to diseases.

The most common diseases are intestinal flagellates (Hexamita), gill worms and skin parasites. Quarantine and preventive treatment with metronidazole and praziquantel are well-established practices among farmers.

Wild (wild-caught) Discus are more difficult to keep than farmed Discus. They require even more extreme parameters and are often carriers of parasites.

Reference values by aquarium type

Related terms