Can killifish live with zebra loaches?

Verdict
Yes

Yes. Killifish and zebra loaches make a good pair. Both are fine at 73–77°F. Plan on at least 30 gal.

KillifishKillifish70–77°F · pH 5.5–7 Zebra loachZebra loach73–79°F · pH 6–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–77°Killifish 70–77°Zebra loach 73–79°
The green band is the temperature range both can live in.
456789Both: 6–7Killifish 5.5–7Zebra loach 6–7.5
The green band is the pH both tolerate.

Size to scale

Killifish · 2.5 inZebra loach · 3.5 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

KillifishZebra loach
Temperature70–77 °F73–79 °F
pH5.5–76–7.5
Adult size2.5 in3.5 in
Minimum tank10 gal30 gal
TemperamentPeacefulPeaceful
Swims atTopBottom
GroupAlone or in pairsGroups of 5+
DietCarnivoreOmnivore

Better tank mates for killifish

All killifish tank mates

Better tank mates for zebra loaches

All zebra loach tank mates

Questions

Can killifish live with zebra loaches?

Yes. Killifish and zebra loaches make a good pair. Both are fine at 73–77°F. Plan on at least 30 gal.

What temperature suits both killifish and zebra loaches?

73–77 °F. Killifish need 70–77 °F, zebra loaches need 73–79 °F.

What size tank do killifish and zebra loaches need together?

At least 30 gal, set by the zebra loach. Add space for each extra fish.