Can koi live with siamese algae eaters?

Verdict

No. Koi and siamese algae eaters should not share a tank. Koi are coldwater animals (59–77°F); siamese algae eaters need 75–79°F. They overlap only at 75–77°F, the edge of both ranges.

Koi59–77°F · pH 7–8.5

Siamese algae eater75–79°F · pH 6.5–7.5

What to watch

Deal breakerKoi are coldwater animals (59–77°F); siamese algae eaters need 75–79°F. They overlap only at 75–77°F, the edge of both ranges.
Watch outA grown koi may treat small siamese algae eaters as food, especially at night.

What works

pH 7–7.5 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	Siamese algae eater
Temperature	59–77 °F	75–79 °F
pH	7–8.5	6.5–7.5
Adult size	24.0 in	6.0 in
Minimum tank	Pond	30 gal
Temperament	Peaceful	Peaceful
Swims at	All levels	Bottom
Group	Groups of 3+	Alone or in pairs
Diet	Omnivore	Herbivore

Better tank mates for koi

All koi tank mates

Better tank mates for siamese algae eaters

All siamese algae eater tank mates

Questions

Can koi live with siamese algae eaters?

No. Koi and siamese algae eaters should not share a tank. Koi are coldwater animals (59–77°F); siamese algae eaters need 75–79°F. They overlap only at 75–77°F, the edge of both ranges.

What temperature suits both koi and siamese algae eaters?

75–77 °F. Koi need 59–77 °F, siamese algae eaters need 75–79 °F.

What size tank do koi and siamese algae eaters need together?

A pond. Koi outgrow indoor tanks.