Colored Glazed Discus

In blackwater quiet, a glazed disc hovers—round as a coin, calm as a shadow.

Colored Glazed Discus: peaceful, show-stopping freshwater cichlids in lacquered metallic tones. Shop 3–9cm juveniles and sub-adults, with expert care tips inside.

• Water conditions (the non-negotiable part): Discus come from the warm, soft, slow-moving waters of the Amazon basin, and they want it warm, soft and above all stable. Aim for 28–30°C (82–86°F) — a few degrees above the average community tank, which is why they thrive in a discus-focused setup rather than a mixed tropical community. Target pH 6.0–7.2, general hardness 3–8 dGH (roughly 50–140 ppm) and carbonate hardness 1–4 dKH. They will tolerate slightly harder, more neutral water provided it is consistent, but the metallic glaze these fish are prized for shows best in soft, slightly acidic conditions, so most keepers blend R/O water with dechlorinated tap and re-mineralise to target. Ammonia and nitrite must read zero at all times, and nitrate should stay below 20 ppm — ideally under 10 ppm. Filtration needs to be generous but gentle: a large canister or sump turning the tank over five to eight times an hour, with the return diffused so you get circulation without a blasting current. Discus dislike strong flow and harsh overhead lighting; both stress them and dull their colour. Stability beats chasing a perfect number every time — a swinging pH or temperature does far more damage than water that is mildly off ideal but constant. Test weekly and keep a log.
• Tank mates: Their peaceful nature makes them easy to mix, with the right neighbours. Discus are slow, deliberate feeders, so avoid anything boisterous or greedy that will strip the food before they arrive. Reliable companions include rummy-nose and cardinal tetras, harlequin and lambchop rasboras, pencilfish, marbled hatchetfish, Sterba's and bronze corydoras, kuhli loaches, Otocinclus and bristlenose plecos. German blue rams, Apistogramma and angelfish can work, but angelfish often out-compete discus at feeding time and can carry pathogens discus are vulnerable to, so quarantine everything strictly. Avoid tiger and serpae barbs and other fin nippers, large or aggressive cichlids such as oscars, jack dempseys and red devils, spiny eels, crayfish and big predatory catfish. Also avoid cool-water species — goldfish, white cloud mountain minnows and most danios — that will suffer at discus temperatures. As for their own kind: discus are shoaling cichlids, and six or more together spreads aggression, builds confidence and produces natural, colourful behaviour instead of one cowering fish. A pecking order will form; it is normal and rarely serious.
• Feeding habits: Discus are carnivorous-leaning omnivores with small stomachs and fast metabolisms — they want frequent, protein-rich meals rather than one big daily dump of flake. Juveniles in the 3–5cm range should be fed four to six small portions a day: frozen or freeze-dried bloodworm, blackworm, mysis, brine shrimp, daphnia, chopped beefheart mix, plus a quality discus granule or soft pellet as the dietary base. Sub-adults and adults of 6–9cm do well on two or three feeds a day. Variety is what produces that saturated, lacquered colour, so rotate foods and include colour-enhancing options rich in astaxanthin, spirulina and carotenoids. Offer only what they clear in a few minutes, siphon out anything uneaten, and skip one feed a week to rest the gut. Live foods are superb but carry real disease risk: culture your own or buy from a trusted source, and never tip shop-bought live food straight into a discus tank. Be patient with new arrivals — they often refuse food for the first few days while settling, and garlic-soaked food or live blackworm usually gets them started.
• Tank setup and acclimatisation: Allow around 200–280 litres (55–75 gallons) for a group of six, with more volume if you keep sub-adults long term. A bare-bottom grow-out tank is the easiest way to keep juveniles clean and well fed; for display, fine sand, driftwood roots and tough plants such as java fern, anubias and amazon swords give cover and a natural sense of security. Keep lighting soft, add floating plants or a shaded area, and make sure the tank is fully cycled before livestock goes in. Drip-acclimatise for 45–60 minutes, matching temperature exactly, then net — never pour — the fish across. Quarantine new arrivals for four to six weeks before they meet your existing stock. On colour: glazed strains are the product of selective breeding, not dyeing or injection, so the metallic sheen you see is genetic and will deepen with good food and stable water.
• Routine care and health: Change 30–50% of the water two to three times a week while growing out juveniles, dropping to one or two large weekly changes for adults. Vacuum the substrate, rinse filter media in tank water only, and keep the temperature and pH steady across changes. Watch for the classic discus complaints — whitespot, gill flukes, hexamita (hole-in-the-head), and the fast-moving bacterial infections sometimes called discus plague. Most of these follow stress, overcrowding or poor water quality, so the first response to a sick discus is a big water change and a review of your parameters. Keep a small hospital tank running, use separate nets and buckets per tank, and never share equipment between a quarantine tank and your display. With steady warmth, soft clean water, varied food and a settled shoal, glazed discus are long-lived, characterful fish that will reward you with years of colour.