Can discus live with killifish?

Verdict
No

No. Discus and killifish should not share a tank. No shared temperature. Discus need 82–88°F, killifish need 70–77°F.

DiscusDiscus82–88°F · pH 5.5–7 KillifishKillifish70–77°F · pH 5.5–7

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Discus 82–88°Killifish 70–77°
The ranges do not meet, so one of them would always be too warm or too cold.
456789Both: 5.5–7Discus 5.5–7Killifish 5.5–7
The green band is the pH both tolerate.

Size to scale

Discus · 6 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

DiscusKillifish
Temperature82–88 °F70–77 °F
pH5.5–75.5–7
Adult size6.0 in2.5 in
Minimum tank55 gal10 gal
TemperamentPeacefulPeaceful
Swims atMiddleTop
GroupGroups of 5+Alone or in pairs
DietCarnivoreCarnivore

Better tank mates for discus

All discus tank mates

Better tank mates for killifish

All killifish tank mates

Questions

Can discus live with killifish?

No. Discus and killifish should not share a tank. No shared temperature. Discus need 82–88°F, killifish need 70–77°F.

What temperature suits both discus and killifish?

None. Discus need 82–88 °F and killifish need 70–77 °F, so the ranges do not meet.

What size tank do discus and killifish need together?

At least 55 gal, set by the discus. Add space for each extra fish.