Can Comet Goldfish and Molly live together?

Comet Goldfish and Molly 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

Comet Goldfish vs Molly

Comet Goldfish

Carassius auratus var. comet

Molly

Poecilia sphenops

Verdict:Not compatible

Side-by-side specs

Goldfish

Family

Livebearers

12″

Adult size

4″

75gal

Min tank

20gal

60–72°F

Temperature

72–82°F

6.5–8

7.5–8.5

peaceful

Temperament

peaceful

Solitary

Schooling

All

Water level

mid

Compatibility notes

warnComet Goldfish and Molly only narrowly overlap in temperature — keep within 72–72°F.
criticalComet Goldfish produces heavy waste and needs cool water — Molly won't tolerate sharing a tank.

Try both in the builder →Compare different species