Can Oscar and Ranchu Goldfish live together?

Oscar and Ranchu Goldfish are not compatible. The comparison on this page runs the same compatibility engine as the tank builder, checking temperature and pH overlap, predation by size, temperament, and known hard-pair conflicts.

Species Comparison

Oscar vs Ranchu Goldfish

Oscar

Astronotus ocellatus

Ranchu Goldfish

Carassius auratus var. ranchu

Verdict:Not compatible

Side-by-side specs

Cichlids

Family

Goldfish

13″

Adult size

7″

75gal

Min tank

30gal

74–81°F

Temperature

65–75°F

6–7.5

6.5–8

aggressive

Temperament

peaceful

Solitary

Schooling

Solitary

mid

Water level

mid

Compatibility notes

warnOscar and Ranchu Goldfish only narrowly overlap in temperature — keep within 74–75°F.
criticalOscar is aggressive and will bully peaceful Ranchu Goldfish.
criticalRanchu Goldfish produces heavy waste and needs cool water — Oscar won't tolerate sharing a tank.

Try both in the builder →Compare different species