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
Swordtail
- Adult size
- 10 cm / 3.9 in
- Tank reference
- 100+ L / 26.4+ US gal
- Group
- 4+
- Zone
- mid
- Temperature
- 22–28°C / 71.6–82.4°F
Water parameter overlap
Behavior and space
A reliable community shoaler that appreciates plants around open swimming space. Active livebearers that need more swimming length than their common shop size suggests.
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 Swordtail?
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.