Can bolivian rams live with harlequin rasboras?

Verdict
Yes

Yes, bolivian rams and harlequin rasboras can live together. Both are fine at 72–79°F. Plan on at least 20 gal.

Bolivian ramBolivian ram72–79°F · pH 6–7.5 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°Bolivian ram 72–79°Harlequin rasbora 72–80°
The green band is the temperature range both can live in.
456789Both: 6–7.5Bolivian ram 6–7.5Harlequin rasbora 6–7.5
The green band is the pH both tolerate.

Size to scale

Bolivian ram · 3 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

Bolivian ramHarlequin rasbora
Temperature72–79 °F72–80 °F
pH6–7.56–7.5
Adult size3.0 in2.0 in
Minimum tank20 gal10 gal
TemperamentPeacefulPeaceful
Swims atBottomMiddle
GroupAlone or in pairsGroups of 6+
DietOmnivoreOmnivore

Better tank mates for bolivian rams

All bolivian ram tank mates

Better tank mates for harlequin rasboras

All harlequin rasbora tank mates

Questions

Can bolivian rams live with harlequin rasboras?

Yes, bolivian rams and harlequin rasboras can live together. Both are fine at 72–79°F. Plan on at least 20 gal.

What temperature suits both bolivian rams and harlequin rasboras?

72–79 °F. Bolivian rams need 72–79 °F, harlequin rasboras need 72–80 °F.

What size tank do bolivian rams and harlequin rasboras need together?

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