Can fancy goldfish live with killifish?

Verdict

Yes, with care

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

Fancy goldfish65–74°F · pH 7–8

Killifish70–77°F · pH 5.5–7

What to watch

Watch outWater chemistry is a squeeze. The only pH that suits both is around 7.

What works

Both are fine at 70–74°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

	Fancy goldfish	Killifish
Temperature	65–74 °F	70–77 °F
pH	7–8	5.5–7
Adult size	6.0 in	2.5 in
Minimum tank	30 gal	10 gal
Temperament	Peaceful	Peaceful
Swims at	All levels	Top
Group	Alone or in pairs	Alone or in pairs
Diet	Omnivore	Carnivore

Better tank mates for fancy goldfish

All fancy goldfish tank mates

Better tank mates for killifish

All killifish tank mates

Questions

Can fancy goldfish live with killifish?

Yes, with care. Fancy goldfish and killifish 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 fancy goldfish and killifish?

70–74 °F. Fancy goldfish need 65–74 °F, killifish need 70–77 °F.

What size tank do fancy goldfish and killifish need together?

At least 30 gal, set by the fancy goldfish. Add space for each extra fish.