Why is my Oscar lying on its side at the bottom of the tank?

Oscars are famous for 'sulking' and may lie on their sides when stressed by large water changes, new decor, or being moved. If water parameters are perfectly fine, it is a behavioural quirk that usually passes in a few hours.

Can I keep an Oscar in a planted tank?

Generally, no. Oscars are notorious for digging up the substrate and outright destroying vegetation. If you want plants, you must use tough species like Java Fern or Anubias tied tightly to heavy pieces of driftwood.

How quickly do Oscars grow?

They grow exceptionally fast. With a high-quality diet and pristine water, a juvenile Oscar can grow roughly 2 to 3 centimetres per month during its first year, reaching 20 centimetres very quickly.

Why does my Oscar thrash and splash at the surface?

They are highly food-motivated and will often splash, thrash, or even jump when begging for food. A heavy, tight-fitting lid is essential to prevent them from leaping entirely out of the aquarium.

Do I need to feed my Oscar live fish?

No, and it is highly discouraged. Live 'feeder fish' like goldfish or rosy reds offer poor nutrition and are major carriers of diseases and parasites. A varied diet of high-quality pellets, earthworms, and frozen prawns is far safer and healthier.

FreshwaterTropicalIntermediate

Oscar

Astronotus ocellatus

A large, intelligent South American cichlid famous for its 'wet pet' personality and voracious appetite.

List this species for sale Find Oscar near me

Ideal Conditions

Temperature: 22 – 27 °C
pH range: 6 – 8
Hardness: 5 – 20 dGH
Adult size: 25 – 35 cm
300L for a single adult, 400L+ for a pair or community: 300 litres+
Lifespan: 10 – 15 years
Diet: Omnivorous predator; requires high-quality cichlid pellets, earthworms, insects, and occasional vegetable matter.
Water flow: moderate
Preferred setup: Large unplanted aquarium with heavy filtration, sandy substrate, and large, securely placed driftwood or smooth rocks.

About the Oscar

The Oscar (Astronotus ocellatus) is one of the most beloved large cichlids in the aquarium hobby. Revered for their high intelligence and dog-like behaviour, they quickly learn to recognise their owners and will readily beg for food at the glass. Because of their impressive adult size and hefty bioload, they demand spacious aquariums and rigorous maintenance routines.

Find Oscar

Search current listings in your chosen area. If none are available, save an alert and we’ll let you know when a match is listed.

Find locally Check compatibility Add to a Setup

Availability alerts only use public sale listings. Adding this species to a Setup updates your private records.

Is it right for your tank?

Check Oscar against a habitat you already keep. We compare water type, temperature, pH, adult size, group needs and everything living there.

Where Oscar comes from

Native range

Amazon River basin, Orinoco River basin

Countries / regions

Brazil, Colombia, Peru, French Guiana

Habitat

Slow-moving, white-water rivers, canals, ponds, and silty lake margins with abundant submerged wood.

Has been introduced to several other countries, including the USA (Florida), where it is considered an invasive species.

Similar species

Jack Dempsey
Rocio octofasciata
Green Terror
Andinoacara rivulatus
Jaguar Cichlid
Parachromis managuensis

We’re adding more full species guides as the catalogue grows.

Compatible tank mates

Reviewed guidance based on this species' recorded traits.

View all compatibility

Silver Dollar
Metynnis argenteus
Fast, robust, and grows large enough not to be considered food by an adult Oscar.
Great
Sailfin Pleco
Pterygoplichthys gibbiceps
Armoured bottom dweller that grows large enough to withstand an Oscar's curiosity and territoriality.
Great
Jack Dempsey
Rocio octofasciata
A similarly sized, robust cichlid; can cohabit successfully in very large tanks, but territorial clashes are possible.
Compatible with caution
Neon Tetra
Paracheirodon innesi
Far too small; will be instantly viewed as prey and eaten.
Not recommended
Angelfish
Pterophyllum scalare
Too delicate and physically fragile to cohabit with a large, boisterous Oscar.
Not recommended

Current marketplace listings

Checking the marketplace…

See all Oscar listings

Public Wanted requests

No open requests for Oscar in this market yet.

Looking for Oscar?

Search current listings near you, or post a wanted request so local sellers know what you’re looking for.

Search Oscar listings Post a wanted request