Can rosy barbs live with black neon tetras?

Verdict
Yes

Yes. Rosy barbs and black neon tetras get along in the same tank. Both are fine at 73–77°F. Plan on at least 30 gal.

Rosy barbRosy barb64–77°F · pH 6–7.5 Black neon tetraBlack neon tetra73–81°F · pH 5.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–77°Rosy barb 64–77°Black neon tetra 73–81°
The green band is the temperature range both can live in.
456789Both: 6–7.5Rosy barb 6–7.5Black neon tetra 5.5–7.5
The green band is the pH both tolerate.

Size to scale

Rosy barb · 4 inBlack neon tetra · 1.5 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

Rosy barbBlack neon tetra
Temperature64–77 °F73–81 °F
pH6–7.55.5–7.5
Adult size4.0 in1.5 in
Minimum tank30 gal15 gal
TemperamentSemi-aggressivePeaceful
Swims atMiddleMiddle
GroupGroups of 6+Groups of 6+
DietOmnivoreOmnivore

Better tank mates for rosy barbs

All rosy barb tank mates

Better tank mates for black neon tetras

All black neon tetra tank mates

Questions

Can rosy barbs live with black neon tetras?

Yes. Rosy barbs and black neon tetras get along in the same tank. Both are fine at 73–77°F. Plan on at least 30 gal.

What temperature suits both rosy barbs and black neon tetras?

73–77 °F. Rosy barbs need 64–77 °F, black neon tetras need 73–81 °F.

What size tank do rosy barbs and black neon tetras need together?

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