Can platies live with rosy barbs?

Verdict
Yes

Yes. Platies and rosy barbs get along in the same tank. Both are fine at 70–77°F. Plan on at least 30 gal.

PlatyPlaty70–80°F · pH 7–8.2 Rosy barbRosy barb64–77°F · pH 6–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 70–77°Platy 70–80°Rosy barb 64–77°
The green band is the temperature range both can live in.
456789Both: 7–7.5Platy 7–8.2Rosy barb 6–7.5
The green band is the pH both tolerate.

Size to scale

Platy · 2.5 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

PlatyRosy barb
Temperature70–80 °F64–77 °F
pH7–8.26–7.5
Adult size2.5 in4.0 in
Minimum tank10 gal30 gal
TemperamentPeacefulSemi-aggressive
Swims atMiddleMiddle
GroupGroups of 3+Groups of 6+
DietOmnivoreOmnivore

Better tank mates for platies

All platy tank mates

Better tank mates for rosy barbs

All rosy barb tank mates

Questions

Can platies live with rosy barbs?

Yes. Platies and rosy barbs get along in the same tank. Both are fine at 70–77°F. Plan on at least 30 gal.

What temperature suits both platies and rosy barbs?

70–77 °F. Platies need 70–80 °F, rosy barbs need 64–77 °F.

What size tank do platies and rosy barbs need together?

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