Can koi live with upside down catfish?

Verdict
Yes, with care

Yes, with care. Koi and upside down catfish can share a tank, but watch one thing. At 24 inches a koi can swallow a small upside down catfish. Fast, alert fish usually stay out of reach.

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–77°Koi 59–77°Upside down catfish 72–79°
The green band is the temperature range both can live in.
456789Both: 7–7.5Koi 7–8.5Upside down catfish 6–7.5
The green band is the pH both tolerate.

Size to scale

Koi · 24 inUpside down catfish · 4 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

KoiUpside down catfish
Temperature59–77 °F72–79 °F
pH7–8.56–7.5
Adult size24.0 in4.0 in
Minimum tankPond30 gal
TemperamentPeacefulPeaceful
Swims atAll levelsBottom
GroupGroups of 3+Groups of 3+
DietOmnivoreOmnivore

Better tank mates for koi

All koi tank mates

Better tank mates for upside down catfish

All upside down catfish tank mates

Questions

Can koi live with upside down catfish?

Yes, with care. Koi and upside down catfish can share a tank, but watch one thing. At 24 inches a koi can swallow a small upside down catfish. Fast, alert fish usually stay out of reach.

What temperature suits both koi and upside down catfish?

72–77 °F. Koi need 59–77 °F, upside down catfish need 72–79 °F.

What size tank do koi and upside down catfish need together?

A pond. Koi outgrow indoor tanks.