Can hillstream loaches live with killifish?

Verdict
Yes

Yes, hillstream loaches and killifish can live together. Both are fine at 70–75°F. Plan on at least 20 gal.

Hillstream loachHillstream loach68–75°F · pH 6.5–7.5 KillifishKillifish70–77°F · pH 5.5–7

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 70–75°Hillstream loach 68–75°Killifish 70–77°
The green band is the temperature range both can live in.
456789Both: 6.5–7Hillstream loach 6.5–7.5Killifish 5.5–7
The green band is the pH both tolerate.

Size to scale

Hillstream loach · 2.5 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

Hillstream loachKillifish
Temperature68–75 °F70–77 °F
pH6.5–7.55.5–7
Adult size2.5 in2.5 in
Minimum tank20 gal10 gal
TemperamentPeacefulPeaceful
Swims atBottomTop
GroupGroups of 3+Alone or in pairs
DietHerbivoreCarnivore

Better tank mates for hillstream loaches

All hillstream loach tank mates

Better tank mates for killifish

All killifish tank mates

Questions

Can hillstream loaches live with killifish?

Yes, hillstream loaches and killifish can live together. Both are fine at 70–75°F. Plan on at least 20 gal.

What temperature suits both hillstream loaches and killifish?

70–75 °F. Hillstream loaches need 68–75 °F, killifish need 70–77 °F.

What size tank do hillstream loaches and killifish need together?

At least 20 gal, set by the hillstream loach. Add space for each extra fish.