Fish comparison
Neon Tetra vs Threadfin Rainbowfish
How the Neon Tetra and Threadfin Rainbowfish compare on care, size, water and temperament, and which fish suits your tank.
By Mike ElmiraUpdated
TL;DR, Neon Tetra vs Threadfin Rainbowfish
The Neon Tetra and the Threadfin Rainbowfish 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 24 to 26 °C and pH 6.5 to 7, so a single tank can suit either one. The Neon Tetra is the more forgiving of the two, which matters if this is an early tank, while the Threadfin Rainbowfish rewards a bit more attention. Read the full care notes on each below and pick the one whose look and pace fit the tank you're building.
Group compatibility overview
Excellent fit
Every key parameter overlaps and no major conflicts surfaced.
4 notes
Temperature
- Neon Tetra20–26 °C
- Threadfin Rainbowfish24–30 °C
pH
- Neon Tetra5.5–7
- Threadfin Rainbowfish6.5–7.5
Hardness
- Neon Tetra1–8 dGH
- Threadfin Rainbowfish5–15 dGH
What to plan for
- Neon Tetra schools, stock at least 10You've planned for 1 neon tetra. Neon Tetra need a group of at least 10 to feel safe and shoal naturally, below that they're stressed and lose colour. Dial up the count, or remove the species.
- Threadfin Rainbowfish schools, stock at least 6You've planned for 1 threadfin rainbowfish. Threadfin Rainbowfish need a group of at least 6 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 |  FishNeon TetraParacheirodon innesi |  FishThreadfin RainbowfishIriatherina werneri |
|---|---|---|
| Category | Fish | Fish |
| Origin | Upper Amazon basin, South America | Northern Australia, southern New Guinea |
| Family | Characidae | Melanotaeniidae |
| Temperature | 20–26 °C | 24–30 °C |
| pH | 5.5–7.0 | 6.5–7.5 |
| Hardness (dGH) | 1–8 | 5–15 |
| Flow rate | Low to Medium | Low to Medium |
| Min tank | 60 L | 60 L |
| Adult size | 3.5–4 cm | 4–5 cm |
| Difficulty | 2 / 5 | 3 / 5 |
| Lifespan | 5–8 yrs | 3–4 yrs |
| Diet | Omnivore | Micropredator |
| Water column | Mid | Mid to Top |
| Schooling | Yes | Yes |
| Plant safe | Yes | Yes |
| Shrimp safe | Yes (with adults; may eat shrimplets) | Yes (adult shrimp) |
Frequently asked questions
Direct answers to the questions search engines and AI assistants surface most often about this species.
Can you keep Neon Tetra and Threadfin Rainbowfish together?
Yes. Their temperature and pH ranges overlap around 24 to 26 °C and pH 6.5 to 7, 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 Neon Tetra or the Threadfin Rainbowfish?
The Neon Tetra is the easier of the two, closer to beginner-friendly, while the Threadfin Rainbowfish leans middle-of-the-road.
Do Neon Tetra and Threadfin Rainbowfish need the same water?
Close to it. Aim for 24 to 26 °C and pH 6.5 to 7 and you're in the shared sweet spot for both. Full ranges are in the table above.
What's the main difference between the Neon Tetra and the Threadfin Rainbowfish?
It comes down to look, size and pace rather than one being flatly better. The table above lays the numbers out row by row.