Ranchu goldfish care
Carassius auratus · Japan, bred from Chinese lionhead goldfish
Ranchu are Japanese fancy goldfish with no dorsal fin, an arched back, a short tail and a hood on the head; Japanese keepers call them the king of goldfish.
- Tank size
- 30 US gal or larger
- Temperature
- 65 to 74 °F (18 to 23 °C)
- Group size
- 2 or more
- Temperament
- Peaceful
- Adult size
- 8 in (including the tail)
- pH
- 7 to 8
- Hardness (GH)
- 6 to 18 dGH
- Lifespan
- 10 to 15 years
- Diet
- Omnivore
- Care level
- Moderate
In a 30 gallon
36¼ × 12⅝ × 16¾ in outsideHow to keep ranchu goldfish
Ranchu are Japanese fancy goldfish with no dorsal fin, an arched back, a short tail and a hood on the head; Japanese keepers call them the king of goldfish. Keep two or more in a 30 gallon or larger tank, wide rather than tall, at 65 to 74 °F with gentle flow, and only with other slow fancy goldfish.
Diet: Omnivore: sinking goldfish pellets, blanched peas and greens, frozen foods. Fish food types compared · how often to feed.
Where they swim: All levels.
Ranchu goldfish tank mates
Share the temperature and water, and neither side eats, nips or bullies the other. Check the full group in the stocking checker.
Fancy goldfish
8 in · 20+ gal · 64–74 °F
Oranda
8 in · 30+ gal · 64–74 °F
Ryukin
8 in · 30+ gal · 64–74 °F
Pearlscale goldfish
8 in · 30+ gal · 65–74 °F
Fantail goldfish
8 in · 30+ gal · 64–74 °F
Black moor
6 in · 30+ gal · 64–74 °F
Lionhead goldfish
6 in · 30+ gal · 64–74 °F
Bubble eye goldfish
4 in · 30+ gal · 65–74 °F
Keep apart
Green neon tetra: No shared temperature: ranchu goldfish need 65 to 74 °F, green neon tetras 75 to 82 °F.
Rummy-nose tetra: No shared temperature: ranchu goldfish need 65 to 74 °F, rummy-nose tetras 75 to 82 °F.- Golden pencilfish: No shared temperature: ranchu goldfish need 65 to 74 °F, golden pencilfish 75 to 82 °F.
Marbled hatchetfish: No shared temperature: ranchu goldfish need 65 to 74 °F, marbled hatchetfish 75 to 82 °F.
Betta: No shared temperature: ranchu goldfish need 65 to 74 °F, bettas 76 to 82 °F.
Dwarf gourami: No shared temperature: ranchu goldfish need 65 to 74 °F, dwarf gouramis 77 to 82 °F.
What a ranchu goldfish tank needs
A tank of 30 US gallons or more (such as the 30 gallon) with a cover, and the equipment below. Ranchu goldfish are comfortable at room temperature, so a heater is optional in a normal home.
As an Amazon Associate I earn from qualifying purchases.
Aqueon PRO QuietFlow Power Filter 20
Rated by the maker for up to 30 US gal, which covers a 30 gallon ranchu goldfish tank without being built for a far bigger one.
Aqueon QuietFlow Internal Power Filter 15–30 gal
Rated by the maker for 15–30 US gal, which covers a 30 gallon ranchu goldfish tank without being built for a far bigger one.
API Freshwater Master Test Kit
Tests ammonia, nitrite, nitrate and pH, the readings that matter most before and after adding ranchu goldfish.
Seachem Prime 100 mL
Removes chlorine and chloramine from tap water at every water change.
Fluval Edge Thermometer
Shows the water temperature at a glance, so you know it stays within 65 to 74 °F.
We don’t list fish food: any good brand of the foods under Diet will do. Plan the whole tank's equipment →
Common ranchu goldfish problems
- Floating upside down or trouble staying level is common in round-bodied goldfish; feed sinking food, keep the water clean, and see a vet if it does not improve.
- The hood can grow over the eyes in some fish; a vet who treats fish can trim it.
Test the water first whenever fish look unwell: see what your readings mean, then match the symptom. For disease, a vet who treats fish can diagnose it and advise treatment.
More to compare
Sources
Name, origin and adult size checked against Wikipedia: Carassius auratus. Temperature, pH, hardness, group size, lifespan and minimum tank size are common hobby guidance, not figures from that article. Ranges are the range the species tolerates; aim for the middle. Minimum tank sizes are for an adult group. Drawings are our own; photo credits follow.
Photo credits
Real photographs from Wikimedia Commons, resized and cropped to fit; each is used under the license named.
- Ranchu goldfish Lerdsuwa, CC BY-SA 4.0, via Wikimedia Commons
- Fancy goldfish Benson Kua, CC BY-SA 2.0, via Wikimedia Commons
- Oranda Lawrencekhoo, CC BY-SA 4.0, via Wikimedia Commons
- Ryukin Lawrencekhoo, CC BY-SA 4.0, via Wikimedia Commons
- Pearlscale goldfish Lerdsuwa, CC BY-SA 3.0, via Wikimedia Commons
- Fantail goldfish Pogrebnoj-Alexandroff, CC BY 3.0, via Wikimedia Commons
- Black moor Riyad Youssef, CC BY 2.5, via Wikimedia Commons
- Lionhead goldfish Roderick Santos, CC BY 2.5, via Wikimedia Commons
- Bubble eye goldfish Angie Torres from Toronto, CC BY-SA 2.0, via Wikimedia Commons
- Green neon tetra Sascha Biedermann, CC BY-SA 2.5, via Wikimedia Commons
- Rummy-nose tetra PierangeloGatto, CC BY-SA 4.0, via Wikimedia Commons
- Marbled hatchetfish Sven Kullander, CC BY-SA 4.0, via Wikimedia Commons
- Betta ivabalk (Pixabay), CC0, via Wikimedia Commons
- Dwarf gourami Quatermass (English Wikipedia), Public domain, via Wikimedia Commons
- Common goldfish ぱたごん, CC BY-SA 3.0, via Wikimedia Commons
- Comet goldfish Michelle Jo (Humanfeather), CC BY 3.0, via Wikimedia Commons
- Shubunkin Rodsan18 at English Wikipedia, CC BY 2.5, via Wikimedia Commons
.jpg){kind=link}
