Can koi live with assassin snails?

Verdict

No. Koi and assassin snails should not share a tank. Koi are coldwater animals (59–77°F); assassin snails need 75–80°F. They overlap only at 75–77°F, the edge of both ranges.

Koi59–77°F · pH 7–8.5

Assassin snail75–80°F · pH 7–8

What to watch

Deal breakerKoi are coldwater animals (59–77°F); assassin snails need 75–80°F. They overlap only at 75–77°F, the edge of both ranges.
Watch outLarge koi crack or pick at small snails. A big mystery snail has better odds than a ramshorn.

What works

pH 7–8 suits both.

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	Assassin snail
Temperature	59–77 °F	75–80 °F
pH	7–8.5	7–8
Adult size	24.0 in	1.0 in
Minimum tank	Pond	5 gal
Temperament	Peaceful	Peaceful
Swims at	All levels	Bottom
Group	Groups of 3+	Alone or in pairs
Diet	Omnivore	Carnivore

Better tank mates for koi

All koi tank mates

Better tank mates for assassin snails

All assassin snail tank mates

Questions

Can koi live with assassin snails?

No. Koi and assassin snails should not share a tank. Koi are coldwater animals (59–77°F); assassin snails need 75–80°F. They overlap only at 75–77°F, the edge of both ranges.

What temperature suits both koi and assassin snails?

75–77 °F. Koi need 59–77 °F, assassin snails need 75–80 °F.

What size tank do koi and assassin snails need together?

A pond. Koi outgrow indoor tanks.