Can harlequin rasboras live with dwarf neon rainbowfish?

Verdict
Yes

Yes. Harlequin rasboras and dwarf neon rainbowfish get along in the same tank. Both are fine at 75–80°F. Plan on at least 20 gal.

Harlequin rasboraHarlequin rasbora72–80°F · pH 6–7.5 Dwarf neon rainbowfishDwarf neon rainbowfish75–82°F · pH 6.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–80°Harlequin rasbora 72–80°Dwarf neon rainbowfish 75–82°
The green band is the temperature range both can live in.
456789Both: 6.5–7.5Harlequin rasbora 6–7.5Dwarf neon rainbowfish 6.5–7.5
The green band is the pH both tolerate.

Size to scale

Harlequin rasbora · 2 inDwarf neon rainbowfish · 2.5 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 rasboraDwarf neon rainbowfish
Temperature72–80 °F75–82 °F
pH6–7.56.5–7.5
Adult size2.0 in2.5 in
Minimum tank10 gal20 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 dwarf neon rainbowfish

All dwarf neon rainbowfish tank mates

Questions

Can harlequin rasboras live with dwarf neon rainbowfish?

Yes. Harlequin rasboras and dwarf neon rainbowfish get along in the same tank. Both are fine at 75–80°F. Plan on at least 20 gal.

What temperature suits both harlequin rasboras and dwarf neon rainbowfish?

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

What size tank do harlequin rasboras and dwarf neon rainbowfish need together?

At least 20 gal, set by the dwarf neon rainbowfish. Add space for each extra fish.