Possible, but with meaningful cautions
Their pH overlap is narrow.
Practical response: Confirm your stable source-water pH sits within the shared range.
Cardinal Tetra
- Adult size
- 5 cm / 2 in
- Tank reference
- 60+ L / 15.9+ US gal
- Group
- 8+
- Zone
- mid
- Temperature
- 23–29°C / 73.4–84.2°F
Platy
- Adult size
- 6 cm / 2.4 in
- Tank reference
- 55+ L / 14.5+ US gal
- Group
- 4+
- Zone
- mid
- Temperature
- 20–26°C / 68–78.8°F
Water parameter overlap
Behavior and space
A warm-water schooling tetra that prefers stable, softer water and a sizeable group. Hardy livebearers that prefer mineral-rich water and can quickly increase in number.
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 Cardinal Tetra live with Platy?
The StockingLab verdict is caution: Their pH overlap is narrow.
Do their temperatures overlap?
23–26°C / 73.4–78.8°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.