Can congo tetras live with killifish?

Verdict
Yes

Yes. Congo tetras and killifish get along in the same tank. Both are fine at 73–77°F. Plan on at least 30 gal.

Congo tetraCongo tetra73–82°F · pH 6–7.5 KillifishKillifish70–77°F · pH 5.5–7

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–77°Congo tetra 73–82°Killifish 70–77°
The green band is the temperature range both can live in.
456789Both: 6–7Congo tetra 6–7.5Killifish 5.5–7
The green band is the pH both tolerate.

Size to scale

Congo tetra · 3 inKillifish · 2.5 in0"1"2"3"4"5"6"
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

Congo tetraKillifish
Temperature73–82 °F70–77 °F
pH6–7.55.5–7
Adult size3.0 in2.5 in
Minimum tank30 gal10 gal
TemperamentPeacefulPeaceful
Swims atMiddleTop
GroupGroups of 6+Alone or in pairs
DietOmnivoreCarnivore

Better tank mates for congo tetras

All congo tetra tank mates

Better tank mates for killifish

All killifish tank mates

Questions

Can congo tetras live with killifish?

Yes. Congo tetras and killifish get along in the same tank. Both are fine at 73–77°F. Plan on at least 30 gal.

What temperature suits both congo tetras and killifish?

73–77 °F. Congo tetras need 73–82 °F, killifish need 70–77 °F.

What size tank do congo tetras and killifish need together?

At least 30 gal, set by the congo tetra. Add space for each extra fish.