Can killifish live with siamese algae eaters?

Verdict
Yes

Yes. Killifish and siamese algae eaters get along in the same tank. Both are fine at 75–77°F. Plan on at least 30 gal.

KillifishKillifish70–77°F · pH 5.5–7 Siamese algae eaterSiamese algae eater75–79°F · pH 6.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–77°Killifish 70–77°Siamese algae eater 75–79°
The green band is the temperature range both can live in.
456789Both: 6.5–7Killifish 5.5–7Siamese algae eater 6.5–7.5
The green band is the pH both tolerate.

Size to scale

Killifish · 2.5 inSiamese algae eater · 6 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

KillifishSiamese algae eater
Temperature70–77 °F75–79 °F
pH5.5–76.5–7.5
Adult size2.5 in6.0 in
Minimum tank10 gal30 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 siamese algae eaters

All siamese algae eater tank mates

Questions

Can killifish live with siamese algae eaters?

Yes. Killifish and siamese algae eaters get along in the same tank. Both are fine at 75–77°F. Plan on at least 30 gal.

What temperature suits both killifish and siamese algae eaters?

75–77 °F. Killifish need 70–77 °F, siamese algae eaters need 75–79 °F.

What size tank do killifish and siamese algae eaters need together?

At least 30 gal, set by the siamese algae eater. Add space for each extra fish.