Cichlid
Meet the oscar
The oscar (Astronotus ocellatus) comes from the Amazon basin in South America. Oscars recognize their owners, beg at the glass and redecorate their tanks, which is why keepers call them the dogs of the fish world. They also grow fast, often reaching about 10 to 12 inches.
Tank size and setup
- Plan on a 75 gallon tank as a practical minimum for one adult, and 125 gallons or more for a pair or a group with tank mates.
- Oscars are messy. Strong filtration matters: many keepers run a large canister plus a second filter.
- Use a secure lid. Oscars can jump.
- Expect them to move decor and uproot plants. Heavy, smooth rock and driftwood work best.
Water
| Parameter | Typical range |
|---|---|
| Temperature | 74 to 81 F |
| pH | 6.0 to 8.0 (stability matters most) |
| Nitrate | As low as you can keep it, ideally under 20 ppm |
Diet
Feed a quality large cichlid pellet as the staple, with frozen foods such as krill, mysis or earthworms for variety. Avoid feeder goldfish. Adults do well with one or two feedings a day.
Tank mates
Good tank mates are large, peaceful to semi aggressive fish that will not fit in an oscar’s mouth: silver dollars, large plecos, severums and other big South American cichlids, given enough space. Small fish will eventually be eaten.
Frequently asked questions
How big of a tank does an oscar need?
A 75 gallon tank is a practical minimum for one adult oscar. A pair or an oscar with tank mates needs 125 gallons or more.
How big do oscars get?
Most aquarium oscars reach about 10 to 12 inches, and some get larger.
How long do oscars live?
With good care, oscars commonly live 10 to 15 years, and some live longer.
What you will need
- 75 gallon or larger tankThe right starting point for one adult oscar.Check price on Amazon
- Large canister filterOscars are messy eaters.Check price on Amazon
- Large cichlid pelletsStaple diet.Check price on Amazon
- Heavy duty lidOscars can jump.Check price on Amazon
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