Can harlequin rasboras live with clown plecos?

Verdict
Yes

Yes. Harlequin rasboras and clown plecos make a good pair. Both are fine at 73–80°F. Plan on at least 20 gal.

Harlequin rasboraHarlequin rasbora72–80°F · pH 6–7.5 Clown plecoClown pleco73–82°F · pH 6.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–80°Harlequin rasbora 72–80°Clown pleco 73–82°
The green band is the temperature range both can live in.
456789Both: 6.5–7.5Harlequin rasbora 6–7.5Clown pleco 6.5–7.5
The green band is the pH both tolerate.

Size to scale

Harlequin rasbora · 2 inClown pleco · 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 rasboraClown pleco
Temperature72–80 °F73–82 °F
pH6–7.56.5–7.5
Adult size2.0 in3.5 in
Minimum tank10 gal20 gal
TemperamentPeacefulPeaceful
Swims atMiddleBottom
GroupGroups of 6+Alone or in pairs
DietOmnivoreHerbivore

Better tank mates for harlequin rasboras

All harlequin rasbora tank mates

Better tank mates for clown plecos

All clown pleco tank mates

Questions

Can harlequin rasboras live with clown plecos?

Yes. Harlequin rasboras and clown plecos make a good pair. Both are fine at 73–80°F. Plan on at least 20 gal.

What temperature suits both harlequin rasboras and clown plecos?

73–80 °F. Harlequin rasboras need 72–80 °F, clown plecos need 73–82 °F.

What size tank do harlequin rasboras and clown plecos need together?

At least 20 gal, set by the clown pleco. Add space for each extra fish.