Can fancy goldfish live with flowerhorns?

Verdict

No. Fancy goldfish and flowerhorns should not share a tank. Fancy goldfish are coldwater animals (65–74°F); flowerhorns need 80–89°F. No temperature suits both.

Fancy goldfish65–74°F · pH 7–8

Flowerhorn80–89°F · pH 7–8

What to watch

Deal breakerFancy goldfish are coldwater animals (65–74°F); flowerhorns need 80–89°F. No temperature suits both.
Deal breakerAn adult flowerhorn is twice the size of a fancy goldfish and will hunt or batter a slow, long-finned fish like this.
Deal breakerFlowerhorns are aggressive and will bully peaceful fancy goldfish.

What works

pH 7–8 suits both.

Water side by side

The ranges do not meet, so one of them would always be too warm or too cold.

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	Flowerhorn
Temperature	65–74 °F	80–89 °F
pH	7–8	7–8
Adult size	6.0 in	12.0 in
Minimum tank	30 gal	75 gal
Temperament	Peaceful	Aggressive
Swims at	All levels	Middle
Group	Alone or in pairs	One per tank
Diet	Omnivore	Carnivore

Better tank mates for fancy goldfish

All fancy goldfish tank mates

Questions

Can fancy goldfish live with flowerhorns?

No. Fancy goldfish and flowerhorns should not share a tank. Fancy goldfish are coldwater animals (65–74°F); flowerhorns need 80–89°F. No temperature suits both.

What temperature suits both fancy goldfish and flowerhorns?

None. Fancy goldfish need 65–74 °F and flowerhorns need 80–89 °F, so the ranges do not meet.

What size tank do fancy goldfish and flowerhorns need together?

At least 75 gal, set by the flowerhorn. Add space for each extra fish.