Common Goldfish
Carassius auratus
Family: Cyprinidae • Origin: East Asia
Goldfish are NOT beginner fish despite reputation. They need 40+ gallons, grow to 12 inches, and live 15+ years. Cold water only — no tropical tankmates.
Min Tank
40 gal
Max Size
12"
Temperature
60-74°F
pH
7-8
Lifespan
15 years
School Size
2+
Swim Level
all
Hardness
10-20 dGH
peacefulbeginneromnivoreschooling
Care Tips
- • NOT a bowl fish — needs 40+ gallons
- • Cold water — no heater, no tropical fish
- • Grows to 12 inches
- • Lives 15-20 years
- • Massive waste producer — heavy filtration
Feeding: Goldfish pellets, vegetables, bloodworms. High waste producer — don't overfeed.
Compatibility Notes: Cold water fish — CANNOT be kept with tropical fish. Need much more space than people think.
Tank Setup & Water Parameters
Tank Requirements
- Minimum Tank Size
- 40 gallons
- Recommended Tank Size
- 75 gallons
- Swimming Level
- all
- Minimum School Size
- 2+ fish
Water Parameters
- Temperature
- 60–74°F
- pH Range
- 7–8
- Hardness (dGH)
- 10–20
- Water Type
- freshwater
Behavior & Temperament
- Temperament
- peaceful
- Aggression Level
- 1/5
- Schooling
- Yes
- Territorial
- No
- Fin Nipper
- No
- Predatory
- No
- Diet Type
- omnivore
- Growth Rate
- fast
Cold water fish — CANNOT be kept with tropical fish. Need much more space than people think.
Breeding
- Breeding Type
- egg layer
- Breeding Difficulty
- easy
- Lifespan
- 15 years
Ideal For
40 galloncold water tankpond
Compatible Tank Mates
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Black Skirt Tetra
Gymnocorymbus ternetzi
70-82°FpH 6-7.515+ gal
peacefulschooling 5+3"
Platy
Xiphophorus maculatus
70-80°FpH 7-810+ gal
peacefulschooling 3+3"
Panda Corydoras
Corydoras panda
68-77°FpH 6-7.510+ gal
peacefulschooling 6+2"
Bristlenose Pleco
Ancistrus cirrhosus
72-82°FpH 6-7.520+ gal
peaceful5"
Amano Shrimp
Caridina multidentata
68-80°FpH 6.5-7.510+ gal
peacefulschooling 4+2"
Mystery Snail
Pomacea bridgesii
68-82°FpH 7-85+ gal
peaceful2.5"
Similar Species
Fancy Goldfish
Carassius auratus (fancy varieties)
65-75°FpH 7-820+ gal
peacefulschooling 2+8"
Peacock Eel
Macrognathus siamensis
72-82°FpH 6.5-7.575+ gal
peaceful12"
Axolotl
Ambystoma mexicanum
60-68°FpH 7-875+ gal
peaceful12"
Congo Tetra
Phenacogrammus interruptus
75-81°FpH 6-7.530+ gal
peacefulschooling 6+3.5"