The fancy goldfish (Carassius auratus) is a peaceful fish that grows to about 8 inches and spends its time all over the tank. It can be kept on its own, in a tank of 30 gallons or more, at 65–72°F and pH 7–8.
30 galsmallest tank
8″adult size
65–72°Ftemperature
7–8pH
1+group size
Peacefultemperament
Good tankmates
Avoid
- ✕Cardinal tetra: Fancy goldfish and Cardinal tetra need different temperatures (65–72°F vs 73–81°F).
- ✕Black skirt tetra: Black skirt tetra nip fins; Fancy goldfish has long fins.
- ✕Serpae tetra: Serpae tetra nip fins; Fancy goldfish has long fins.
- ✕Glowlight tetra: Fancy goldfish and Glowlight tetra need different temperatures (65–72°F vs 74–82°F).
- ✕Rummy-nose tetra: Fancy goldfish and Rummy-nose tetra need different temperatures (65–72°F vs 75–84°F).
- ✕Congo tetra: Fancy goldfish and Congo tetra need different temperatures (65–72°F vs 73–82°F).
- ✕Marbled hatchetfish: Fancy goldfish and Marbled hatchetfish need different temperatures (65–72°F vs 75–82°F).
- ✕Golden pencilfish: Fancy goldfish and Golden pencilfish need different temperatures (65–72°F vs 75–82°F).
From TankCoach's own species data: common hobby guidance for adults, rounded. Individual fish vary. Not veterinary advice.