Can crayfish live with rosy barbs?

Verdict
Yes

Yes, crayfish and rosy barbs can live together. Both are fine at 65–77°F. Plan on at least 30 gal.

CrayfishCrayfish65–77°F · pH 6.5–8 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: 65–77°Crayfish 65–77°Rosy barb 64–77°
The green band is the temperature range both can live in.
456789Both: 6.5–7.5Crayfish 6.5–8Rosy barb 6–7.5
The green band is the pH both tolerate.

Size to scale

Crayfish · 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

CrayfishRosy barb
Temperature65–77 °F64–77 °F
pH6.5–86–7.5
Adult size5.0 in4.0 in
Minimum tank20 gal30 gal
TemperamentAggressiveSemi-aggressive
Swims atBottomMiddle
GroupOne per tankGroups of 6+
DietOmnivoreOmnivore

Better tank mates for crayfish

All crayfish tank mates

Better tank mates for rosy barbs

All rosy barb tank mates

Questions

Can crayfish live with rosy barbs?

Yes, crayfish and rosy barbs can live together. Both are fine at 65–77°F. Plan on at least 30 gal.

What temperature suits both crayfish and rosy barbs?

65–77 °F. Crayfish need 65–77 °F, rosy barbs need 64–77 °F.

What size tank do crayfish and rosy barbs need together?

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