Personality
Oscars are the most intelligent and interactive cichlid in the trade. They recognize their owner, swim to the front of the tank when you approach, and can be hand-fed within weeks.
They also rearrange the tank constantly — moving rocks, uprooting plants, and tipping over décor. Aquascaping an oscar tank is a losing battle.
Tank Size
Minimum 75-gallon (4 ft long) for a single oscar. 125-gallon for a pair. Adults reach 12–14 inches and need swimming room.
Tank must have a tight-fitting lid. Oscars jump when startled and during feeding excitement.
Water Parameters
Temperature: 74–80°F (23–27°C).
pH: 6.0–8.0 (very tolerant).
GH: 5–20 (very tolerant).
Nitrates: under 40 ppm. Oscars are tolerant of imperfect water but quality affects coloration.
Filtration: 3× tank volume per hour. Oscars are the messiest cichlids.
Diet
Carnivore-leaning omnivore. Hikari Cichlid Gold or Massivore pellets as staple. Earthworms, frozen krill, prawn, and occasional crickets for variety.
Avoid feeder goldfish — disease and thiaminase risk.
Feed 2× daily for juveniles, 1× daily for adults. Skip a day per week.
Color Varieties
Tiger oscar (red and black, classic), red oscar (mostly red), albino oscar (white with red), lemon oscar (yellow), veil-tail oscar.
Color intensity depends on diet, mood, and water quality. A stressed oscar fades to gray; a healthy oscar in a planted tank glows red and orange.
Tank Mates
Compatible: large plecos, large silver dollars, severums, large catfish, jack dempseys (in 180+ gallon), green terror cichlids.
Risky: anything small enough to eat (under 4 inches), aggressive cichlids in small tanks.
Two oscars in a 125-gallon often fight unless they bond as a breeding pair.