Can corydoras live with harlequin rasboras?

Verdict
Yes

Yes. Corydoras and harlequin rasboras make a good pair. Both are fine at 72–79°F. Plan on at least 20 gal.

CorydorasCorydoras72–79°F · pH 6–7.8 Harlequin rasboraHarlequin rasbora72–80°F · pH 6–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–79°Corydoras 72–79°Harlequin rasbora 72–80°
The green band is the temperature range both can live in.
456789Both: 6–7.5Corydoras 6–7.8Harlequin rasbora 6–7.5
The green band is the pH both tolerate.

Size to scale

Corydoras · 2.5 inHarlequin rasbora · 2 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

CorydorasHarlequin rasbora
Temperature72–79 °F72–80 °F
pH6–7.86–7.5
Adult size2.5 in2.0 in
Minimum tank20 gal10 gal
TemperamentPeacefulPeaceful
Swims atBottomMiddle
GroupGroups of 6+Groups of 6+
DietOmnivoreOmnivore

Better tank mates for corydoras

All corydoras tank mates

Better tank mates for harlequin rasboras

All harlequin rasbora tank mates

Questions

Can corydoras live with harlequin rasboras?

Yes. Corydoras and harlequin rasboras make a good pair. Both are fine at 72–79°F. Plan on at least 20 gal.

What temperature suits both corydoras and harlequin rasboras?

72–79 °F. Corydoras need 72–79 °F, harlequin rasboras need 72–80 °F.

What size tank do corydoras and harlequin rasboras need together?

At least 20 gal, set by the corydoras. Add space for each extra fish.