Can killifish live with clown plecos?

Verdict
Yes

Yes, killifish and clown plecos can live together. Both are fine at 73–77°F. Plan on at least 20 gal.

KillifishKillifish70–77°F · pH 5.5–7 Clown plecoClown pleco73–82°F · pH 6.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–77°Killifish 70–77°Clown pleco 73–82°
The green band is the temperature range both can live in.
456789Both: 6.5–7Killifish 5.5–7Clown pleco 6.5–7.5
The green band is the pH both tolerate.

Size to scale

Killifish · 2.5 inClown pleco · 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

KillifishClown pleco
Temperature70–77 °F73–82 °F
pH5.5–76.5–7.5
Adult size2.5 in3.5 in
Minimum tank10 gal20 gal
TemperamentPeacefulPeaceful
Swims atTopBottom
GroupAlone or in pairsAlone or in pairs
DietCarnivoreHerbivore

Better tank mates for killifish

All killifish tank mates

Better tank mates for clown plecos

All clown pleco tank mates

Questions

Can killifish live with clown plecos?

Yes, killifish and clown plecos can live together. Both are fine at 73–77°F. Plan on at least 20 gal.

What temperature suits both killifish and clown plecos?

73–77 °F. Killifish need 70–77 °F, clown plecos need 73–82 °F.

What size tank do killifish and clown plecos need together?

At least 20 gal, set by the clown pleco. Add space for each extra fish.