Arowana tank mates
Osteoglossum bicirrhosum
5 rated pairings from the Arowana care guide. Compatibility here means water, temperament, tank zone and adult size all line up — the note on each card says why. Arowana needs at least 250 gallons on its own; every companion adds to that.
Good matches
1 · Compatible with normal care — watch space and numbers.Use caution
3 · Works in the right setup; read the note before combining.Severum
Heros severus
55 gal min · 8" adult · Semi-aggressive
Can work in very large tanks but may compete for space; monitor for aggression
Oscar
Astronotus ocellatus
75 gal min · 12" adult · Aggressive
Both are large and semi-aggressive; only suitable in very spacious tanks with careful monitoring
Red Tail Catfish
Phractocephalus hemioliopterus
1000 gal min · 48" adult · Aggressive
Similar size requirements but both are predatory; risk of predation on smaller fish
Avoid
1 · Not recommended — one of them will suffer.Also recommended alongside Arowana
Species whose own guides list Arowana as a tank mate.
Planning this tank?
Run the whole stock list through the calculator — it checks bioload and schooling numbers, not just pairings.