Red discus vs Redbreast acara: can they live together?

Verdict: Not recommended

The Redbreast acara is aggressive towards other fish.
The Red discus grows about twice as long as the Redbreast acara; watch for bullying or predation.
Both are comfortable at 27–29°C (81–84°F).
A pH of 6.0–6.5 suits both.

Side by side

	Red discus	Redbreast acara
Adult size	18 cm (7.1 in)	7.5 cm (3 in)
Minimum tank	210 L (55 US gal)	115 L (30 US gal)
Temperature	27–33°C (81–91°F)	25–29°C (77–84°F)
pH	4.2–6.5	6.0–7.5
Hardness	–	1–20 dGH (18–357 ppm)
Temperament	Peaceful	Aggressive
Care level	Moderate	Easy
Diet	Carnivore	Omnivore