Fish comparison
Black Neon Tetra vs Buenos Aires Tetra
How the Black Neon Tetra and Buenos Aires Tetra compare on care, size, water and temperament, and which fish suits your tank.
By Mike ElmiraUpdated
TL;DR, Black Neon Tetra vs Buenos Aires Tetra
The Black Neon Tetra and the Buenos Aires Tetra are close cousins, both in the Hyphessobrycon group, so at a glance they ask for a lot of the same things. Both are happy somewhere around 22 to 28 °C and pH 6 to 7.5, so a single tank can suit either one. Neither is harder than the other to keep, so the choice comes down to look and stocking rather than skill. If tank space is tight, the Black Neon Tetra needs less room to feel settled; give the Buenos Aires Tetra 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
- Black Neon Tetra22–28 °C
- Buenos Aires Tetra18–28 °C
pH
- Black Neon Tetra5.5–7.5
- Buenos Aires Tetra6–8
Hardness
- Black Neon Tetra2–12 dGH
- Buenos Aires Tetra5–20 dGH
What to plan for
- Black Neon Tetra schools, stock at least 8You've planned for 1 black neon tetra. Black Neon 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.
- Buenos Aires Tetra schools, stock at least 8You've planned for 1 buenos aires tetra. Buenos Aires 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.
- 100% 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 |  FishBlack Neon TetraHyphessobrycon herbertaxelrodi |  FishBuenos Aires TetraHyphessobrycon anisitsi |
|---|---|---|
| Category | Fish | Fish |
| Origin | Paraguay River basin, Brazil | Paraguay, Uruguay, southern Brazil |
| Family | Characidae | Characidae |
| Temperature | 22–28 °C | 18–28 °C |
| pH | 5.5–7.5 | 6.0–8.0 |
| Hardness (dGH) | 2–12 | 5–20 |
| Flow rate | Low to Medium | Medium to high |
| Min tank | 60 L | 150 L |
| Adult size | 3–4 cm | 7–10 cm |
| Difficulty | 1 / 5 | 1 / 5 |
| Lifespan | 5 yrs | 5–7 yrs |
| Diet | Omnivore | Omnivore (heavy plant-grazer) |
| Water column | Mid | Mid |
| Schooling | Yes | Yes |
| Plant safe | Yes | No (will defoliate soft plants) |
| 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 Black Neon Tetra and Buenos Aires Tetra together?
Yes. Their temperature and pH ranges overlap around 22 to 28 °C and pH 6 to 7.5, 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 Black Neon Tetra or the Buenos Aires Tetra?
They sit at the same care level, both very easy, so neither is the obvious beginner pick. The decision is really about the look you're after.
Do Black Neon Tetra and Buenos Aires Tetra need the same water?
Close to it. Aim for 22 to 28 °C and pH 6 to 7.5 and you're in the shared sweet spot for both. Full ranges are in the table above.
What's the main difference between the Black Neon Tetra and the Buenos Aires Tetra?
Temperament is the big one. The Black Neon Tetra is peaceful and the Buenos Aires Tetra is semi-aggressive, which changes who you can house them with.