Can siamese algae eaters live with harlequin rasboras?

Verdict
Yes

Yes. Siamese algae eaters and harlequin rasboras get along in the same tank. Both are fine at 75–79°F. Plan on at least 30 gal.

Siamese algae eaterSiamese algae eater75–79°F · pH 6.5–7.5 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: 75–79°Siamese algae eater 75–79°Harlequin rasbora 72–80°
The green band is the temperature range both can live in.
456789Both: 6.5–7.5Siamese algae eater 6.5–7.5Harlequin rasbora 6–7.5
The green band is the pH both tolerate.

Size to scale

Siamese algae eater · 6 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

Siamese algae eaterHarlequin rasbora
Temperature75–79 °F72–80 °F
pH6.5–7.56–7.5
Adult size6.0 in2.0 in
Minimum tank30 gal10 gal
TemperamentPeacefulPeaceful
Swims atBottomMiddle
GroupAlone or in pairsGroups of 6+
DietHerbivoreOmnivore

Better tank mates for siamese algae eaters

All siamese algae eater tank mates

Better tank mates for harlequin rasboras

All harlequin rasbora tank mates

Questions

Can siamese algae eaters live with harlequin rasboras?

Yes. Siamese algae eaters and harlequin rasboras get along in the same tank. Both are fine at 75–79°F. Plan on at least 30 gal.

What temperature suits both siamese algae eaters and harlequin rasboras?

75–79 °F. Siamese algae eaters need 75–79 °F, harlequin rasboras need 72–80 °F.

What size tank do siamese algae eaters and harlequin rasboras need together?

At least 30 gal, set by the siamese algae eater. Add space for each extra fish.