Can koi live with chili rasboras?

Verdict
No

No. Koi and chili rasboras should not share a tank. Koi are coldwater animals (59–77°F); chili rasboras need 75–82°F. They overlap only at 75–77°F, the edge of both ranges.

What to watch

Water side by side

55°60°65°70°75°80°85°90°Both: 75–77°Koi 59–77°Chili rasbora 75–82°
The green band is the temperature range both can live in.
456789Both: 7Koi 7–8.5Chili rasbora 4–7
The green band is the pH both tolerate.

Size to scale

Koi · 24 inChili rasbora · 0.8 in0"6"12"18"24"
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

KoiChili rasbora
Temperature59–77 °F75–82 °F
pH7–8.54–7
Adult size24.0 in0.8 in
Minimum tankPond5 gal
TemperamentPeacefulPeaceful
Swims atAll levelsMiddle
GroupGroups of 3+Groups of 8+
DietOmnivoreCarnivore

Better tank mates for koi

All koi tank mates

Better tank mates for chili rasboras

All chili rasbora tank mates

Questions

Can koi live with chili rasboras?

No. Koi and chili rasboras should not share a tank. Koi are coldwater animals (59–77°F); chili rasboras need 75–82°F. They overlap only at 75–77°F, the edge of both ranges.

What temperature suits both koi and chili rasboras?

75–77 °F. Koi need 59–77 °F, chili rasboras need 75–82 °F.

What size tank do koi and chili rasboras need together?

A pond. Koi outgrow indoor tanks.