Can harlequin rasboras live with assassin snails?

Verdict
Yes

Yes. Harlequin rasboras and assassin snails get along in the same tank. Both are fine at 75–80°F. Plan on at least 10 gal.

Harlequin rasboraHarlequin rasbora72–80°F · pH 6–7.5 Assassin snailAssassin snail75–80°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°Assassin snail 75–80°
The green band is the temperature range both can live in.
456789Both: 7–7.5Harlequin rasbora 6–7.5Assassin snail 7–8
The green band is the pH both tolerate.

Size to scale

Harlequin rasbora · 2 inAssassin snail · 1 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 rasboraAssassin snail
Temperature72–80 °F75–80 °F
pH6–7.57–8
Adult size2.0 in1.0 in
Minimum tank10 gal5 gal
TemperamentPeacefulPeaceful
Swims atMiddleBottom
GroupGroups of 6+Alone or in pairs
DietOmnivoreCarnivore

Better tank mates for harlequin rasboras

All harlequin rasbora tank mates

Better tank mates for assassin snails

All assassin snail tank mates

Questions

Can harlequin rasboras live with assassin snails?

Yes. Harlequin rasboras and assassin snails get along in the same tank. Both are fine at 75–80°F. Plan on at least 10 gal.

What temperature suits both harlequin rasboras and assassin snails?

75–80 °F. Harlequin rasboras need 72–80 °F, assassin snails need 75–80 °F.

What size tank do harlequin rasboras and assassin snails need together?

At least 10 gal, set by the harlequin rasbora. Add space for each extra fish.