Diamond Tetra
Moenkhausia pittieri
Diamond Tetra (Moenkhausia pittieri) is a peaceful freshwater fish that reaches about 6 cm (2.4 in) and swims in open water in a shoal. It wants 75–82°F (24–28°C) and pH 5.5–7, is kept in groups of 6 or more, and needs a tank of at least 68 L (18 gal).
At a glance
| Type | Fish |
|---|---|
| Adult size | 6 cm (2.4 in) |
| Minimum tank | 68 L (18 gal) |
| Group size | 6 or more |
| Temperature | 75–82°F (24–28°C) |
| pH | 5.5–7 |
| Temperament | Peaceful |
| Lifespan | 3–6 years |
| Eats shrimp | Yes |
Before it goes in
- Diamond Tetra needs at least 68 L (18 gal). The smallest size in this library that clears that is the 20 Gallon High.
- Keep 6 or more. Below that it hides, colours down and is far more likely to be picked on.
- It eats shrimp. Cherry Shrimp, Crystal Red Shrimp and Bamboo Shrimp are on the menu.
- It is the wrong size to share a tank with Goldfish, Axolotl and Oscar: it ends up as food.
- It holds at 75–82°F (24–28°C). That shares a window with Betta and Cherry Shrimp, but not with Goldfish and Dojo Loach.
- It nips fins, so long-finned fish are a bad match.
- A group of 6 takes up roughly 67% of what a 20 Gallon High will comfortably hold, so plan the rest of the stock around it.
What tank size does it need?
At least 68 L (18 gal). The smallest size here that clears it is the 20 Gallon High.
How many should I keep?
6 or more. Fewer than that and it spends its time hiding instead of out in the open.
Will it eat shrimp?
Yes. Shrimp are food to it, so pick one or the other.
What water does it want?
75–82°F (24–28°C), pH 5.5–7.
How long does it live?
3–6 years in a tank that suits it. That is how long you are signing up for.
Good tank mates
- Tank mates from this library that share its temperature window, are peaceful and eat neither it nor its young: Bristlenose Pleco, Celestial Pearl Danio, Molly, Otocinclus and Ramshorn Snail.
- Plants that hold up with it: Hygrophila corymbosa 'Siamensis', Water Sprite, Anubias nana 'Petite' and Cryptocoryne wendtii.
Often compared with
| Diamond Tetra | Black Skirt Tetra | Bleeding Heart Tetra | |
|---|---|---|---|
| Adult size | 6 cm | 6 cm | 6 cm |
| Min tank | 68 L | 68 L | 81 L |
| Group | 6+ | 12+ | 8+ |
| Temperature | 75–82°F (24–28°C) | 68–79°F (20–26°C) | 70–82°F (21–28°C) |
| Eats shrimp | Yes | Yes | — |
More livestock
Sources (4) · checked Sep 2026
- What it eats, Mature tankfishlaboratory.com
- What it eatsaquariumsource.com
- Mature tankseriouslyfish.com
- fishkeepingworld.com