Fish comparison
Cardinal Tetra vs Paradise Fish
How the Cardinal Tetra and Paradise Fish compare on care, size, water and temperament, and which fish suits your tank.
By Mike ElmiraUpdated
TL;DR, Cardinal Tetra vs Paradise Fish
The Cardinal Tetra and the Paradise Fish come up together a lot when people are choosing a fish, and they are close enough to weigh side by side. Both are happy somewhere around 23 to 26 °C and pH 6 to 6.5, so a single tank can suit either one. The Paradise Fish is the more forgiving of the two, which matters if this is an early tank, while the Cardinal Tetra rewards a bit more attention. For a calm community the gentler Cardinal Tetra slots in more easily.
Group compatibility overview
Excellent fit
Every key parameter overlaps and no major conflicts surfaced.
3 notes
Temperature
- Cardinal Tetra23–27 °C
- Paradise Fish16–26 °C
pH
- Cardinal Tetra4.5–6.5
- Paradise Fish6–8
Hardness
- Cardinal Tetra1–6 dGH
- Paradise Fish5–20 dGH
What to plan for
- Cardinal Tetra schools, stock at least 8You've planned for 1 cardinal tetra. Cardinal Tetra need a group of at least 8 to feel safe and shoal naturally, below that they're stressed and lose colour. Dial up the count, or remove the species.
- No bottom teamNo bottom-dwelling fish or shrimp. A small group of corydoras or a shrimp colony picks up leftover food and keeps detritus in check.
- 67% of your fish swim in the midHeavy concentration in a single zone. Spreading stocking across all three levels makes the tank read fuller for the same bioload.
Full attributes
Every parameter, side by side| Parameter |  FishCardinal TetraParacheirodon axelrodi |  FishParadise FishMacropodus opercularis |
|---|---|---|
| Category | Fish | Fish |
| Origin | Upper Orinoco and Rio Negro basins | East Asia (China, Korea, Vietnam, Taiwan) |
| Family | Characidae | Osphronemidae |
| Temperature | 23–27 °C | 16–26 °C |
| pH | 4.5–6.5 | 6.0–8.0 |
| Hardness (dGH) | 1–6 | 5–20 |
| Flow rate | Low | Still to Low |
| Min tank | 75 L | 75 L |
| Adult size | 4–5 cm | 8–10 cm |
| Difficulty | 3 / 5 | 2 / 5 |
| Lifespan | 4–6 yrs | 6–8 yrs |
| Diet | Omnivore | Carnivore-leaning omnivore |
| Water column | Mid | Mid to Top |
| Schooling | Yes | No (single or carefully chosen pair) |
| Plant safe | Yes | Yes |
| Shrimp safe | Mostly (may eat shrimplets) | No |
Frequently asked questions
Direct answers to the questions search engines and AI assistants surface most often about this species.
Can you keep Cardinal Tetra and Paradise Fish together?
Yes. Their temperature and pH ranges overlap around 23 to 26 °C and pH 6 to 6.5, so one set of water conditions keeps both comfortable. Match group sizes and cover the usual planted-tank basics and they share a tank fine.
Which is easier to keep, the Cardinal Tetra or the Paradise Fish?
The Paradise Fish is the easier of the two, closer to beginner-friendly, while the Cardinal Tetra leans middle-of-the-road.
Do Cardinal Tetra and Paradise Fish need the same water?
Close to it. Aim for 23 to 26 °C and pH 6 to 6.5 and you're in the shared sweet spot for both. Full ranges are in the table above.
What's the main difference between the Cardinal Tetra and the Paradise Fish?
Temperament is the big one. The Cardinal Tetra is peaceful and the Paradise Fish is aggressive, which changes who you can house them with.