Can cardinal tetras live with rosy barbs?

Verdict
Yes, with care

Yes, with care. Cardinal tetras and rosy barbs can share a tank, but watch one thing. They only share 76–77°F. Keep the heater set there and steady.

Cardinal tetraCardinal tetra76–84°F · pH 4.6–7 Rosy barbRosy barb64–77°F · pH 6–7.5

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Both: 76–77°Cardinal tetra 76–84°Rosy barb 64–77°
The green band is the temperature range both can live in.
456789Both: 6–7Cardinal tetra 4.6–7Rosy barb 6–7.5
The green band is the pH both tolerate.

Size to scale

Cardinal tetra · 2 inRosy barb · 4 in0"1"2"3"4"5"6"
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 tetraRosy barb
Temperature76–84 °F64–77 °F
pH4.6–76–7.5
Adult size2.0 in4.0 in
Minimum tank20 gal30 gal
TemperamentPeacefulSemi-aggressive
Swims atMiddleMiddle
GroupGroups of 6+Groups of 6+
DietOmnivoreOmnivore

Better tank mates for cardinal tetras

All cardinal tetra tank mates

Better tank mates for rosy barbs

All rosy barb tank mates

Questions

Can cardinal tetras live with rosy barbs?

Yes, with care. Cardinal tetras and rosy barbs can share a tank, but watch one thing. They only share 76–77°F. Keep the heater set there and steady.

What temperature suits both cardinal tetras and rosy barbs?

76–77 °F. Cardinal tetras need 76–84 °F, rosy barbs need 64–77 °F.

What size tank do cardinal tetras and rosy barbs need together?

At least 30 gal, set by the rosy barb. Add space for each extra fish.