Can oscars live with killifish?
Verdict
No
No. Oscars and killifish should not share a tank. An adult oscar eats fish that fit in its mouth, and at 2.5 inches killifish do.
What to watch
- Deal breakerAn adult oscar eats fish that fit in its mouth, and at 2.5 inches killifish do.
- Watch outOscars grow to 12 inches and need 75 gallons, far more than a tank set up for killifish.
What works
- Both are fine at 74–77°F.
- pH 6–7 suits both.
- They use different parts of the tank: oscars the mid, killifish the top.
Water side by side
Size to scale
Care at a glance
| Oscar | Killifish | |
|---|---|---|
| Temperature | 74–81 °F | 70–77 °F |
| pH | 6–8 | 5.5–7 |
| Adult size | 12.0 in | 2.5 in |
| Minimum tank | 75 gal | 10 gal |
| Temperament | Semi-aggressive | Peaceful |
| Swims at | Middle | Top |
| Group | Alone or in pairs | Alone or in pairs |
| Diet | Carnivore | Carnivore |
Better tank mates for oscars
Common plecoYes
Clown loachYes
Black ghost knifeYes
BichirYes
Elephant nose fishYes
Chinese algae eaterYes
Better tank mates for killifish
Questions
Can oscars live with killifish?
No. Oscars and killifish should not share a tank. An adult oscar eats fish that fit in its mouth, and at 2.5 inches killifish do.
What temperature suits both oscars and killifish?
74–77 °F. Oscars need 74–81 °F, killifish need 70–77 °F.
What size tank do oscars and killifish need together?
At least 75 gal, set by the oscar. Add space for each extra fish.