Can rosy barbs live with electric blue acaras?

Verdict
Yes

Yes. Rosy barbs and electric blue acaras get along in the same tank. Both are fine at 72–77°F. Plan on at least 30 gal.

Rosy barbRosy barb64–77°F · pH 6–7.5 Electric blue acaraElectric blue acara72–82°F · pH 6.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–77°Rosy barb 64–77°Electric blue acara 72–82°
The green band is the temperature range both can live in.
456789Both: 6.5–7.5Rosy barb 6–7.5Electric blue acara 6.5–7.5
The green band is the pH both tolerate.

Size to scale

Rosy barb · 4 inElectric blue acara · 6 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 barbElectric blue acara
Temperature64–77 °F72–82 °F
pH6–7.56.5–7.5
Adult size4.0 in6.0 in
Minimum tank30 gal30 gal
TemperamentSemi-aggressiveSemi-aggressive
Swims atMiddleMiddle
GroupGroups of 6+Alone or in pairs
DietOmnivoreOmnivore

Better tank mates for rosy barbs

All rosy barb tank mates

Better tank mates for electric blue acaras

All electric blue acara tank mates

Questions

Can rosy barbs live with electric blue acaras?

Yes. Rosy barbs and electric blue acaras get along in the same tank. Both are fine at 72–77°F. Plan on at least 30 gal.

What temperature suits both rosy barbs and electric blue acaras?

72–77 °F. Rosy barbs need 64–77 °F, electric blue acaras need 72–82 °F.

What size tank do rosy barbs and electric blue acaras need together?

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