Can rams live with harlequin rasboras?

Verdict
Yes, with care

Yes, with care. Rams and harlequin rasboras can share a tank, but watch one thing. They only share 80°F. Keep the heater set there and steady.

German blue ramGerman blue ram80–86°F · pH 5–7 Harlequin rasboraHarlequin rasbora72–80°F · pH 6–7.5

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Both: 80°German blue ram 80–86°Harlequin rasbora 72–80°
The green band is the temperature range both can live in.
456789Both: 6–7German blue ram 5–7Harlequin rasbora 6–7.5
The green band is the pH both tolerate.

Size to scale

German blue ram · 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

German blue ramHarlequin rasbora
Temperature80–86 °F72–80 °F
pH5–76–7.5
Adult size2.5 in2.0 in
Minimum tank20 gal10 gal
TemperamentPeacefulPeaceful
Swims atBottomMiddle
GroupAlone or in pairsGroups of 6+
DietOmnivoreOmnivore

Better tank mates for rams

All german blue ram tank mates

Better tank mates for harlequin rasboras

All harlequin rasbora tank mates

Questions

Can rams live with harlequin rasboras?

Yes, with care. Rams and harlequin rasboras can share a tank, but watch one thing. They only share 80°F. Keep the heater set there and steady.

What temperature suits both rams and harlequin rasboras?

80–80 °F. Rams need 80–86 °F, harlequin rasboras need 72–80 °F.

What size tank do rams and harlequin rasboras need together?

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