Family: Cyprinidae
Rohu — a Cyprinidae from China and South Asia. Reaches 150–220 cm; keep at 21–27 °C.
Labeo rohita is a Cyprinidae from China and South Asia. In the wild it prefers clear streams and rivers over gravel; in the aquarium it stays mostly peaceful. Plan on 150–220 cm of adult fish at 21–27 °C. Related profiles: Labeo bata, Labeo boggut, Labeo calbasu.
Realistically, it's a pond fish, not an aquarium fish. Rohu is one of South Asia's most important food carp, reaching 1.5–2.2 m and 40+ kg; the 500 L profile figure is a theoretical floor. Its proper home is an outdoor pool — either you have a substantial garden pond, or engage with it at the aquaculture level rather than behind glass.
Very fast — a classic farmed fast-grower. Fry reach 30–50 cm and 0.5–1 kg in year one, and market size (1–2 kg) within two to three years. That growth means its appetite, waste output, and oxygen demand are engineered to 'pig' standards — any aquarium is overwhelmed within months by size and metabolism.
Omnivore with a herbivorous tilt: algae, aquatic plants, plankton, detritus. In captivity use sinking general-purpose pellets as the staple with blanched spinach, pumpkin, and peas as variety. It's a mid-column forager, habitually intercepting sinking food — floating pellets are wasted on it.
Subtropical — happiest at 21–27 °C, tolerating brief cooler spells but not hard winters. Outdoor ponds in southern China overwinter naturally; around the Yangtze, deepen water past 1.5 m or move fish indoors. Above 30 °C, watch aeration — big cyprinids suffocate collectively on hot, stagnant nights.
Yes — that's the classic South Asian polyculture: rohu, catla, and silver carp partition the water column. In display ponds it coexists peacefully with comparably large cyprinids (grass carp, black carp, big koi), provided water volume, low density, and generous feeding. There's no true peace among hungry giants.
Nine times out of ten: oxygen. Large cyprinids consume enormous oxygen overnight; hot, muggy, algae-heavy ponds suffocate fish in the early morning. Emergency: aerate or change water immediately. Prevention: control density, stop overfeeding, and boost nighttime aeration in summer. If gasping comes with dark color and isolation, suspect water quality or gill disease.
Wild fish are river spawners keyed to monsoon floods — specific hydrological cues (rising water, current, temperature swing) in vast water bodies. Artificial breeding uses hormone injection and flow-through hatcheries; home conditions can't replicate it. Pond fish mature annually without producing fry, much like koi.
Rohu is silvery-gray, more streamlined and laterally compressed, mouth pointing down-forward, strictly a food fish. Koi are ornamental selections of common carp — gaudy colors, deep bodies. Same family, different destinies: one exists for protein, the other for display. They pond-mix fine, but don't expect food-grade rohu to act like a pet.
Tough but heavy-loading: pH 6.5–7.5, GH 5–15, 21–27 °C. Parameter tolerance is excellent; the real challenge is pollution load — a 5 kg rohu out-pollutes dozens of tropical fish. Design filtration like a farm pond: mechanical plus aeration plus regular water changes, with biofiltration scaled to the fish's body weight.
Decide where the adult will live first. A 10–15 cm fry is cute; in two years it's a half-meter giant. Before buying, confirm you have a pond of several tonnes, aeration, and household buy-in for a food fish occupying resources long-term. It's livestock logic, not pet logic — the reason most buyers give up.