Can oscars live with rummy nose tetras?

Verdict
No

No. Oscars and rummy nose tetras should not share a tank. An adult oscar eats fish that fit in its mouth, and at 2 inches rummy nose tetras do.

OscarOscar74–81°F · pH 6–8 Rummy nose tetraRummy nose tetra75–84°F · pH 5.5–7

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–81°Oscar 74–81°Rummy nose tetra 75–84°
The green band is the temperature range both can live in.
456789Both: 6–7Oscar 6–8Rummy nose tetra 5.5–7
The green band is the pH both tolerate.

Size to scale

Oscar · 12 inRummy nose tetra · 2 in0"2"4"6"8"10"12"
Adult length in an aquarium. A fish can swallow anything that fits in its mouth, roughly a third to half its own length for predators.

Care at a glance

OscarRummy nose tetra
Temperature74–81 °F75–84 °F
pH6–85.5–7
Adult size12.0 in2.0 in
Minimum tank75 gal20 gal
TemperamentSemi-aggressivePeaceful
Swims atMiddleMiddle
GroupAlone or in pairsGroups of 6+
DietCarnivoreOmnivore

Better tank mates for oscars

All oscar tank mates

Better tank mates for rummy nose tetras

All rummy nose tetra tank mates

Questions

Can oscars live with rummy nose tetras?

No. Oscars and rummy nose tetras should not share a tank. An adult oscar eats fish that fit in its mouth, and at 2 inches rummy nose tetras do.

What temperature suits both oscars and rummy nose tetras?

75–81 °F. Oscars need 74–81 °F, rummy nose tetras need 75–84 °F.

What size tank do oscars and rummy nose tetras need together?

At least 75 gal, set by the oscar. Add space for each extra fish.