Can harlequin rasboras live with yellow labs?

Verdict
Yes, with care

Yes, with care. Harlequin rasboras and yellow labs can share a tank, but watch one thing. Different water: harlequin rasboras want pH 6–7.5, yellow labs want pH 7.8–8.6.

Harlequin rasboraHarlequin rasbora72–80°F · pH 6–7.5 Electric yellow cichlidElectric yellow cichlid75–82°F · pH 7.8–8.6

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–80°Harlequin rasbora 72–80°Electric yellow cichlid 75–82°
The green band is the temperature range both can live in.
456789Harlequin rasbora 6–7.5Electric yellow cichlid 7.8–8.6
No pH suits both. One would live in the wrong water all the time.

Size to scale

Harlequin rasbora · 2 inElectric yellow cichlid · 4 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 rasboraElectric yellow cichlid
Temperature72–80 °F75–82 °F
pH6–7.57.8–8.6
Adult size2.0 in4.0 in
Minimum tank10 gal40 gal
TemperamentPeacefulSemi-aggressive
Swims atMiddleAll levels
GroupGroups of 6+Groups of 4+
DietOmnivoreOmnivore

Better tank mates for harlequin rasboras

All harlequin rasbora tank mates

Better tank mates for yellow labs

All electric yellow cichlid tank mates

Questions

Can harlequin rasboras live with yellow labs?

Yes, with care. Harlequin rasboras and yellow labs can share a tank, but watch one thing. Different water: harlequin rasboras want pH 6–7.5, yellow labs want pH 7.8–8.6.

What temperature suits both harlequin rasboras and yellow labs?

75–80 °F. Harlequin rasboras need 72–80 °F, yellow labs need 75–82 °F.

What size tank do harlequin rasboras and yellow labs need together?

At least 40 gal, set by the electric yellow cichlid. Add space for each extra fish.