Fish comparison
Neon Tetra vs Red-Tailed Black Shark
How the Neon Tetra and Red-Tailed Black Shark compare on care, size, water and temperament, and which fish suits your tank.
By Mike ElmiraUpdated
TL;DR, Neon Tetra vs Red-Tailed Black Shark
The Neon Tetra and the Red-Tailed Black Shark 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 22 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 Red-Tailed Black Shark rewards a bit more attention. If tank space is tight, the Neon Tetra needs less room to feel settled; give the Red-Tailed Black Shark the nod when you have the litres to spare.
Group compatibility overview
Excellent fit
Every key parameter overlaps and no major conflicts surfaced.
2 notes
Temperature
- Neon Tetra20–26 °C
- Red-Tailed Black Shark22–26 °C
pH
- Neon Tetra5.5–7
- Red-Tailed Black Shark6.5–7.5
Hardness
- Neon Tetra1–8 dGH
- Red-Tailed Black Shark5–15 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.
- 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 |  FishRed-Tailed Black SharkEpalzeorhynchos bicolor |
|---|---|---|
| Category | Fish | Fish |
| Origin | Upper Amazon basin, South America | Thailand (Chao Phraya basin), critically endangered in the wild |
| Family | Characidae | Cyprinidae |
| Temperature | 20–26 °C | 22–26 °C |
| pH | 5.5–7.0 | 6.5–7.5 |
| Hardness (dGH) | 1–8 | 5–15 |
| Flow rate | Low to Medium | Medium |
| Min tank | 60 L | 200 L |
| Adult size | 3.5–4 cm | 12–15 cm |
| Difficulty | 2 / 5 | 3 / 5 |
| Lifespan | 5–8 yrs | 6–8 yrs |
| Diet | Omnivore | Omnivore (heavy on algae and plant matter) |
| Water column | Mid | Bottom to Mid |
| Schooling | Yes | No |
| Plant safe | Yes | Yes (mostly) |
| Shrimp safe | Yes (with adults; may eat shrimplets) | No (will hunt) |
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 Red-Tailed Black Shark together?
Yes. Their temperature and pH ranges overlap around 22 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 Red-Tailed Black Shark?
The Neon Tetra is the easier of the two, closer to beginner-friendly, while the Red-Tailed Black Shark leans middle-of-the-road.
Do Neon Tetra and Red-Tailed Black Shark need the same water?
Close to it. Aim for 22 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 Red-Tailed Black Shark?
Temperament is the big one. The Neon Tetra is peaceful and the Red-Tailed Black Shark is territorial when breeding, which changes who you can house them with.