Can silver dollars live with rosy barbs?

Verdict
Yes

Yes, silver dollars and rosy barbs can live together. Both are fine at 75–77°F. Plan on at least 75 gal.

Silver dollarSilver dollar75–82°F · pH 5–7 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: 75–77°Silver dollar 75–82°Rosy barb 64–77°
The green band is the temperature range both can live in.
456789Both: 6–7Silver dollar 5–7Rosy barb 6–7.5
The green band is the pH both tolerate.

Size to scale

Silver dollar · 6 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

Silver dollarRosy barb
Temperature75–82 °F64–77 °F
pH5–76–7.5
Adult size6.0 in4.0 in
Minimum tank75 gal30 gal
TemperamentPeacefulSemi-aggressive
Swims atMiddleMiddle
GroupGroups of 5+Groups of 6+
DietHerbivoreOmnivore

Better tank mates for silver dollars

All silver dollar tank mates

Better tank mates for rosy barbs

All rosy barb tank mates

Questions

Can silver dollars live with rosy barbs?

Yes, silver dollars and rosy barbs can live together. Both are fine at 75–77°F. Plan on at least 75 gal.

What temperature suits both silver dollars and rosy barbs?

75–77 °F. Silver dollars need 75–82 °F, rosy barbs need 64–77 °F.

What size tank do silver dollars and rosy barbs need together?

At least 75 gal, set by the silver dollar. Add space for each extra fish.