Can harlequin rasboras live with zebra loaches?

Verdict
Yes

Yes, harlequin rasboras and zebra loaches can live together. Both are fine at 73–79°F. Plan on at least 30 gal.

Harlequin rasboraHarlequin rasbora72–80°F · pH 6–7.5 Zebra loachZebra loach73–79°F · pH 6–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–79°Harlequin rasbora 72–80°Zebra loach 73–79°
The green band is the temperature range both can live in.
456789Both: 6–7.5Harlequin rasbora 6–7.5Zebra loach 6–7.5
The green band is the pH both tolerate.

Size to scale

Harlequin rasbora · 2 inZebra loach · 3.5 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 rasboraZebra loach
Temperature72–80 °F73–79 °F
pH6–7.56–7.5
Adult size2.0 in3.5 in
Minimum tank10 gal30 gal
TemperamentPeacefulPeaceful
Swims atMiddleBottom
GroupGroups of 6+Groups of 5+
DietOmnivoreOmnivore

Better tank mates for harlequin rasboras

All harlequin rasbora tank mates

Better tank mates for zebra loaches

All zebra loach tank mates

Questions

Can harlequin rasboras live with zebra loaches?

Yes, harlequin rasboras and zebra loaches can live together. Both are fine at 73–79°F. Plan on at least 30 gal.

What temperature suits both harlequin rasboras and zebra loaches?

73–79 °F. Harlequin rasboras need 72–80 °F, zebra loaches need 73–79 °F.

What size tank do harlequin rasboras and zebra loaches need together?

At least 30 gal, set by the zebra loach. Add space for each extra fish.