Fish comparison
Ember Tetra vs Threadfin Rainbowfish
How the Ember Tetra and Threadfin Rainbowfish compare on care, size, water and temperament, and which fish suits your tank.
By Mike ElmiraUpdated
TL;DR, Ember Tetra vs Threadfin Rainbowfish
The Ember 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 29 °C and pH 6.5 to 7, so a single tank can suit either one. The Ember 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. If tank space is tight, the Ember Tetra needs less room to feel settled; give the Threadfin Rainbowfish the nod when you have the litres to spare.
Group compatibility overview
Excellent fit
Every key parameter overlaps and no major conflicts surfaced.
4 notes
Temperature
- Ember Tetra23–29 °C
- Threadfin Rainbowfish24–30 °C
pH
- Ember Tetra5.5–7
- Threadfin Rainbowfish6.5–7.5
Hardness
- Ember Tetra1–10 dGH
- Threadfin Rainbowfish5–15 dGH
What to plan for
- Ember Tetra schools, stock at least 8You've planned for 1 ember tetra. Ember 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.
- 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 |  FishEmber TetraHyphessobrycon amandae |  FishThreadfin RainbowfishIriatherina werneri |
|---|---|---|
| Category | Fish | Fish |
| Origin | Rio das Mortes basin, Brazil | Northern Australia, southern New Guinea |
| Family | Characidae | Melanotaeniidae |
| Temperature | 23–29 °C | 24–30 °C |
| pH | 5.5–7.0 | 6.5–7.5 |
| Hardness (dGH) | 1–10 | 5–15 |
| Flow rate | Low | Low to Medium |
| Min tank | 40 L | 60 L |
| Adult size | 2 cm | 4–5 cm |
| Difficulty | 2 / 5 | 3 / 5 |
| Lifespan | 2–4 yrs | 3–4 yrs |
| Diet | Omnivore | Micropredator |
| Water column | Mid | Mid to Top |
| Schooling | Yes | Yes |
| Plant safe | Yes | Yes |
| Shrimp safe | Yes (adults safe with adult shrimp) | 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 Ember Tetra and Threadfin Rainbowfish together?
Yes. Their temperature and pH ranges overlap around 24 to 29 °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 Ember Tetra or the Threadfin Rainbowfish?
The Ember Tetra is the easier of the two, closer to beginner-friendly, while the Threadfin Rainbowfish leans middle-of-the-road.
Do Ember Tetra and Threadfin Rainbowfish need the same water?
Close to it. Aim for 24 to 29 °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 Ember Tetra and the Threadfin Rainbowfish?
Space. The Ember Tetra wants about 40 litres minimum and the Threadfin Rainbowfish around 60, so tank size can settle it.