Can cardinal tetras live with mollies?

Verdict

Yes, with care

Yes, with care. Cardinal tetras and mollies can share a tank, but watch one thing. Different water: cardinal tetras want pH 4.6–7, mollies want pH 7.5–8.5.

Cardinal tetra76–84°F · pH 4.6–7

Molly72–82°F · pH 7.5–8.5

What to watch

Watch outDifferent water: cardinal tetras want pH 4.6–7, mollies want pH 7.5–8.5.

What works

Both are fine at 76–82°F.
They use different parts of the tank: cardinal tetras the mid, mollies the top.

Water side by side

The green band is the temperature range both can live in.

No pH suits both. One would live in the wrong water all the time.

Size to scale

Adult length in an aquarium. A fish can swallow anything that fits in its mouth, roughly a third to half its own length for predators.

Care at a glance

	Cardinal tetra	Molly
Temperature	76–84 °F	72–82 °F
pH	4.6–7	7.5–8.5
Adult size	2.0 in	4.0 in
Minimum tank	20 gal	20 gal
Temperament	Peaceful	Peaceful
Swims at	Middle	Top
Group	Groups of 6+	Groups of 3+
Diet	Omnivore	Omnivore

Better tank mates for cardinal tetras

All cardinal tetra tank mates

Better tank mates for mollies

All molly tank mates

Questions

Can cardinal tetras live with mollies?

Yes, with care. Cardinal tetras and mollies can share a tank, but watch one thing. Different water: cardinal tetras want pH 4.6–7, mollies want pH 7.5–8.5.

What temperature suits both cardinal tetras and mollies?

76–82 °F. Cardinal tetras need 76–84 °F, mollies need 72–82 °F.

What size tank do cardinal tetras and mollies need together?

At least 20 gal, set by the cardinal tetra. Add space for each extra fish.