Can harlequin rasboras live with boesemani rainbowfish?

Verdict
Yes

Yes. Harlequin rasboras and boesemani rainbowfish make a good pair. Both are fine at 75–80°F. Plan on at least 30 gal.

Harlequin rasboraHarlequin rasbora72–80°F · pH 6–7.5 Boesemani rainbowfishBoesemani rainbowfish75–82°F · pH 7–8

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–80°Harlequin rasbora 72–80°Boesemani rainbowfish 75–82°
The green band is the temperature range both can live in.
456789Both: 7–7.5Harlequin rasbora 6–7.5Boesemani rainbowfish 7–8
The green band is the pH both tolerate.

Size to scale

Harlequin rasbora · 2 inBoesemani rainbowfish · 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

Harlequin rasboraBoesemani rainbowfish
Temperature72–80 °F75–82 °F
pH6–7.57–8
Adult size2.0 in4.0 in
Minimum tank10 gal30 gal
TemperamentPeacefulPeaceful
Swims atMiddleMiddle
GroupGroups of 6+Groups of 6+
DietOmnivoreOmnivore

Better tank mates for harlequin rasboras

All harlequin rasbora tank mates

Better tank mates for boesemani rainbowfish

All boesemani rainbowfish tank mates

Questions

Can harlequin rasboras live with boesemani rainbowfish?

Yes. Harlequin rasboras and boesemani rainbowfish make a good pair. Both are fine at 75–80°F. Plan on at least 30 gal.

What temperature suits both harlequin rasboras and boesemani rainbowfish?

75–80 °F. Harlequin rasboras need 72–80 °F, boesemani rainbowfish need 75–82 °F.

What size tank do harlequin rasboras and boesemani rainbowfish need together?

At least 30 gal, set by the boesemani rainbowfish. Add space for each extra fish.