Least Killifish
Least Killifish is a peaceful freshwater fish that needs a tank of at least 5 gallons (19 L), water at 68-79°F (20-26°C) and a pH of 7-8.
Also searched as: least killifish, heterandria formosa
Quick facts
Tiny North American native. Livebearer. Hardy nano fish.
| Minimum tank | 5 gallons (19 L) |
|---|---|
| Temperature | 68-79°F (20-26°C) |
| pH | 7-8 |
| Temperament | Peaceful |
| Swim level | Middle |
| Group size | 6 or more together |
| Tank type | Freshwater |
Good tank mates
Ranked by water overlap and temperament, using the same checks as the MyAquaLog compatibility tool.
- Mystery Snailmin tank 5 gal
Temperature overlap 68-79°F, pH overlap 7.2-8. Both species are peaceful.
- Nerite Snailmin tank 5 gal
Temperature overlap 68-79°F, pH overlap 7-8. Both species are peaceful.
- Siamese Algae Eatermin tank 30 gal
Temperature overlap 75-79°F, pH overlap 7-8. Both species are peaceful.
- Bladder Snailmin tank 5 gal
Temperature overlap 68-79°F, pH overlap 7-8. Both species are peaceful.
- Ghost Shrimpmin tank 5 gal
Temperature overlap 68-79°F, pH overlap 7-8. Both species are peaceful.
- Pond Snailmin tank 5 gal
Temperature overlap 68-79°F, pH overlap 7-8. Both species are peaceful.
- Ramshorn Snailmin tank 5 gal
Temperature overlap 68-79°F, pH overlap 7-8. Both species are peaceful.
- Trumpet Snailmin tank 5 gal
Temperature overlap 68-79°F, pH overlap 7-8. Both species are peaceful.
Avoid with
Pairings that fail the temperament, water-overlap or known-conflict checks.
- Skunk Loachmin tank 30 gal
Aggressive species will harass or eat peaceful fish; temperature overlap 79°F is too narrow.
- Flowerhorn Cichlidmin tank 70 gal
Aggressive species will harass or eat peaceful fish; no temperature overlap (68-79°F vs 80-86°F).
Aggressive species will harass or eat peaceful fish.
Oscar Fishmin tank 55 galPea Puffermin tank 5 galWhisker Shrimpmin tank 10 gal
Check your own tank
These lists compare one species against the rest of the database. Your stock list, tank size and bioload change the answer, so log your own tank.
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