Can koi live with otocinclus?

Verdict
Yes, with care

Yes, with care. Koi and otocinclus can share a tank, but watch one thing. At 24 inches a koi can swallow a small otocinclus. 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°Otocinclus 72–79°
The green band is the temperature range both can live in.
456789Both: 7–7.5Koi 7–8.5Otocinclus 6–7.5
The green band is the pH both tolerate.

Size to scale

Koi · 24 inOtocinclus · 2 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

KoiOtocinclus
Temperature59–77 °F72–79 °F
pH7–8.56–7.5
Adult size24.0 in2.0 in
Minimum tankPond20 gal
TemperamentPeacefulPeaceful
Swims atAll levelsBottom
GroupGroups of 3+Groups of 6+
DietOmnivoreHerbivore

Better tank mates for koi

All koi tank mates

Better tank mates for otocinclus

All otocinclus tank mates

Questions

Can koi live with otocinclus?

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

What temperature suits both koi and otocinclus?

72–77 °F. Koi need 59–77 °F, otocinclus need 72–79 °F.

What size tank do koi and otocinclus need together?

A pond. Koi outgrow indoor tanks.