TankmateChecker

Can koi live with ember tetras?

Verdict

Yes, with care

Yes, with care. Koi and ember tetras can share a tank, but watch one thing. Water chemistry is a squeeze. The only pH that suits both is around 7.

Koi

Koi59–77°F · pH 7–8.5

Ember tetra

Ember tetra73–84°F · pH 5.5–7

What to watch

Watch outWater chemistry is a squeeze. The only pH that suits both is around 7.
Watch outAt 24 inches a koi can swallow a small ember tetra. Fast, alert fish usually stay out of reach.

What works

Both are fine at 73–77°F.

Water side by side

The green band is the temperature range both can live in.

The green band is the pH both tolerate.

Size to scale

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

	Koi	Ember tetra
Temperature	59–77 °F	73–84 °F
pH	7–8.5	5.5–7
Adult size	24.0 in	0.8 in
Minimum tank	Pond	5 gal
Temperament	Peaceful	Peaceful
Swims at	All levels	Middle
Group	Groups of 3+	Groups of 6+
Diet	Omnivore	Omnivore

Better tank mates for koi

All koi tank mates

Better tank mates for ember tetras

All ember tetra tank mates

Questions

Can koi live with ember tetras?

Yes, with care. Koi and ember tetras can share a tank, but watch one thing. Water chemistry is a squeeze. The only pH that suits both is around 7.

What temperature suits both koi and ember tetras?

73–77 °F. Koi need 59–77 °F, ember tetras need 73–84 °F.

What size tank do koi and ember tetras need together?

A pond. Koi outgrow indoor tanks.