Can killifish live with blue gouramis?

Verdict
Yes

Yes. Killifish and blue gouramis get along in the same tank. Both are fine at 72–77°F. Plan on at least 30 gal.

KillifishKillifish70–77°F · pH 5.5–7 Blue gouramiBlue gourami72–82°F · pH 6–8

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–77°Killifish 70–77°Blue gourami 72–82°
The green band is the temperature range both can live in.
456789Both: 6–7Killifish 5.5–7Blue gourami 6–8
The green band is the pH both tolerate.

Size to scale

Killifish · 2.5 inBlue gourami · 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

KillifishBlue gourami
Temperature70–77 °F72–82 °F
pH5.5–76–8
Adult size2.5 in5.0 in
Minimum tank10 gal30 gal
TemperamentPeacefulSemi-aggressive
Swims atTopTop
GroupAlone or in pairsAlone or in pairs
DietCarnivoreOmnivore

Better tank mates for killifish

All killifish tank mates

Better tank mates for blue gouramis

All blue gourami tank mates

Questions

Can killifish live with blue gouramis?

Yes. Killifish and blue gouramis get along in the same tank. Both are fine at 72–77°F. Plan on at least 30 gal.

What temperature suits both killifish and blue gouramis?

72–77 °F. Killifish need 70–77 °F, blue gouramis need 72–82 °F.

What size tank do killifish and blue gouramis need together?

At least 30 gal, set by the blue gourami. Add space for each extra fish.