Harlequin Rasbora vs Guppy: can they live together?

A structured comparison of water overlap, adult size, social needs and behavioral risk.

good

Generally compatible on core signals

No major temperature, pH, size or behavioural conflict is flagged by the planning model.

Practical response: Still observe individual behaviour and verify species-specific care before purchase.

Harlequin Rasbora

Adult size
4.5 cm / 1.8 in
Tank reference
50+ L / 13.2+ US gal
Group
8+
Zone
mid
Temperature
22–28°C / 71.6–82.4°F

Guppy

Adult size
5 cm / 2 in
Tank reference
40+ L / 10.6+ US gal
Group
3+
Zone
top
Temperature
22–28°C / 71.6–82.4°F

Water parameter overlap

Temperature
22–28°C / 71.6–82.4°F shared range
pH
pH 7.0–7.5 shared range

Behavior and space

A reliable community shoaler that appreciates plants around open swimming space. A prolific livebearer; plan for fry or single-sex groups and avoid persistent fin-nippers.

A compatibility answer should also consider the actual tank dimensions, number of each fish, filtration, planting and other occupants. Two species can be reasonable together in a long, structured aquarium yet become a poor pairing when compressed into a small footprint.

Common questions

Can Harlequin Rasbora live with Guppy?

The StockingLab verdict is good: No major temperature, pH, size or behavioural conflict is flagged by the planning model.

Do their temperatures overlap?

22–28°C / 71.6–82.4°F shared range.

Should I trust compatibility calculators completely?

No. Individual behavior, sex ratios, breeding condition, aquascape and tank size can change the outcome. Use the result to identify risks, then verify care requirements before purchase.