Fancy goldfish
Carassius auratus · family Cyprinidae
This page covers fancy goldfish (fantails, orandas, ryukins, ranchus and similar). Common and comet goldfish grow much larger: See common goldfish.
Fancy goldfish (Carassius auratus) are the round-bodied, long-finned goldfish from Southern China, including fantails, orandas, ryukins and ranchus. They are peaceful coldwater fish that grow to 6–8 inches and can live 10–20 years, and they need a tank of at least 20 gallons. The most important thing to know is that they make a lot of waste and don't tolerate poor water, so a roomy, well-filtered, fully cycled tank matters more than anything else. Care is moderate rather than easy.
Edited by Marin Hale · last reviewed October 29, 2026 · How we check facts
What can live with a fancy goldfish?
Verdicts against every species in our database, from our compatibility rules. How verdicts work
| Verdict | Species | Why | Tank |
|---|---|---|---|
| Good match | Another fancy goldfish | No problems found: water, size, fins and temperament all check out. | 20 gal+ |
| Good match | Zebra nerite snail | No problems found: water, size, fins and temperament all check out. | 20 gal+ |
| Maybe | Common goldfish | Common goldfish are fast and outcompete slow fancy goldfish for food, and they grow much larger. Most keepers house them separately. | 75 gal+ |
| Avoid | Angelfish | Fancy goldfish need cool water; angelfish need tropical water. | — |
| Avoid | Betta fish | Fancy goldfish need cool water; betta fish need tropical water. | — |
| Avoid | Cherry shrimp | Cherry shrimp prefer softer water (4–8 dGH) than fancy goldfish (8–18 dGH). | — |
| Avoid | Ember tetra | Fancy goldfish need cool water; ember tetras need tropical water. | — |
| Avoid | Guppy | Fancy goldfish need cool water; guppies need tropical water. | — |
| Avoid | Neon tetra | Fancy goldfish need cool water; neon tetras need tropical water. | — |
| Avoid | Pygmy corydoras | Fancy goldfish need cool water; pygmy corydoras need tropical water. | — |
| Avoid | Tiger barb | Fancy goldfish need cool water; tiger barbs need tropical water. | — |
Setup and care
| Heater | No heater. Fancy goldfish are coolwater fish (65–74°F); keep the tank out of direct sun. |
|---|---|
| Feeding | Goldfish flakes/granules, live/frozen treats; only what they eat in 2-3 minutes, once or twice a day |
| Substrate | Avoid jagged or crushed glass gravel; they forage in substrate |
| New tanks | Add only to an established, cycled tank. Not for a brand-new setup. |
| Males vs females | Males develop tubercles (white spots) on gill covers and pectoral fins in breeding season; females have deeper bodies |
| Male:female ratio | 2 males to 1 female (for breeding) |
| Breeding | Most breed in captivity, esp. ponds; adults may eat young; some fancy forms can't breed naturally |
- Produce a large amount of waste that can quickly reach toxic levels
- Rapid temperature changes can kill them, especially in small tanks
- Touching damages the protective slime coat
- Temperatures under about 10 °C (50 °F) are dangerous to fancy varieties
- Temperatures over 30 °C (86 °F) can harm goldfish
- Never keep in bowls, small aquariums or unfiltered containers
Care tips
- Use a mature, fully cycled tank with powerful filtration and aeration, because fancy goldfish are stressed by even small amounts of ammonia and nitrite.
- Never keep them in a bowl, a small aquarium or an unfiltered container.
- Keep the flow gentle and spread out, since they are not great swimmers, and leave the tank fairly open because they have trouble seeing and maneuvering.
- Choose smooth ornaments and avoid jagged or crushed glass gravel, as sharp edges tear fins and eye sacs and these fish forage in the substrate.
Questions
Do fancy goldfish need a heater?
They are coldwater fish that tolerate 65–74°F, with 68–72°F ideal, so a heater isn't automatically needed if your room keeps the tank in that range. What matters most is avoiding sudden temperature swings, drafts and heat sources, since rapid changes can kill them, especially in small tanks.
What do fancy goldfish eat?
They are omnivores and do well on goldfish flakes or granules, with live or frozen treats now and then. Feed once or twice a day, only as much as they eat in 2–3 minutes, because constipation and other gut problems are common in fancy goldfish.
What fish can live with fancy goldfish?
Other fancy goldfish and zebra nerite snails are the safe choices. Common goldfish are a caution, because they are fast, outcompete slow fancy goldfish for food and grow much larger, so most keepers house them separately. Tropical fish such as angelfish, bettas, guppies, neon and ember tetras, pygmy corydoras and tiger barbs are a no, mainly because they need warmer water. Cherry shrimp are also a no, since goldfish will hunt and eat them.
How big do fancy goldfish get and how big a tank do they need?
Adults reach 6–8 inches, and they need at least 20 gallons. They produce a lot of waste, so more water volume helps keep conditions stable. Common and comet goldfish grow much larger, so check the common goldfish page if that's what you have.
Can fancy goldfish breed, and how can you tell males from females?
Most breed in captivity, especially in ponds, laying adhesive eggs on plants or a spawning mop, though some fancy forms can't breed naturally and adults may eat the young. In breeding season males develop white tubercles on the gill covers and pectoral fins, while females have deeper bodies. For breeding, keep 2 males to 1 female.
Sources
Each value is cross-checked across the references below. Where they disagreed, an editor chose a value and recorded why.
- Goldfish (en.wikipedia.org)
- Goldfish Care Guide (www.aqueon.com)
- How to look after fancy goldfish - OATA (ornamentalfish.org)
- The Carassius auratus Known As Oranda (www.qualitymarine.com)
- GBIF taxonomy record
- Wikidata entry
Where each value comes from (20 facts)
| Fact | What each source says |
|---|---|
| Temperature editor decision | en.wikipedia.org: “The optimum temperature for goldfish is between 20 and 22 °C (68 and 72 °F).” aqueon.com: “The optimum temperature for fancy goldfish is 68° to 74° F, while comets and shubunkins should be kept between 60° and 70°F.” ornamentalfish.org: “Temperature: between 4-25°C, 15-23°C is optimal” qualitymarine.com: “Goldfish like cool (think room temperature here, high 60's low 70's Fahrenheit), clean water in aquariums.” |
| Adult size editor decision | en.wikipedia.org: “Wild goldfish typically grow to between 4.7 inches (12 cm) and 8.7 inches (22 cm) but can reach 16 inches (41 cm).” ornamentalfish.org: “Fancy goldfish do not grow as large as common goldfish and are unlikely to grow larger than 20cm.” qualitymarine.com: “Goldfish are highly variable, but will range from six to seven inches usually when fully grown.” |
| Smallest tank editor decision | en.wikipedia.org: “Smaller fantail goldfish should have about 10 US gallons (38 L; 8.3 imp gal) per goldfish.” aqueon.com: “adult fancy goldfish should have at least 10 gallons per adult fish” ornamentalfish.org: “An adult Goldfish should be kept in at least a 100 litre aquarium, allowing for an extra 50 litres per additional adult fish” qualitymarine.com: “A minimum of a 40 gallon aquarium should be considered for keeping Orandas” |
| Safe with plants | en.wikipedia.org: “Because goldfish eat live plants” aqueon.com: “Larger goldfish will eat many types of live plants, with the possible exception of Cryptocorynes, Java fern and Anubias” ornamentalfish.org: “Fancy goldfish can readily eat live plants” qualitymarine.com: “will root around in the substrate and also eat plants as they see fit.” |
| Water type | en.wikipedia.org: “The goldfish is classified as a coldwater fish, and can live in unheated aquaria” aqueon.com: “Considered cold water fish, goldfish can also be kept in heated aquariums.” ornamentalfish.org: “Although fancy goldfish are coldwater fish, they do not tolerate extreme fluctuations in water temperature” |
| Breeding type | en.wikipedia.org: “Their eggs are adhesive and attach to aquatic vegetation, typically dense plants such as Cabomba or Elodea or a spawning mop.” aqueon.com: “Goldfish are egg scatterers and are known to spawn in home aquariums.” ornamentalfish.org: “The fish will lay eggs in plants or a spawning mop which should be removed to another tank afterwards” qualitymarine.com: “lots of places for them to lay eggs (spawning mops will work here if you don't have any other plants or flat surfaces for them to lay eggs on)” |
| Native to | en.wikipedia.org: “Native to China, the goldfish is a relatively small member of the genus Carassius” aqueon.com: “belong to the Family Cyprinidae and are native to Eastern Asia” qualitymarine.com: “their ancestors likely came from Central Asia.” |
| Breeding | en.wikipedia.org: “Most goldfish breed in captivity, particularly in pond settings.” aqueon.com: “They provide no parental care after the eggs are laid.” ornamentalfish.org: “fancy goldfish are notorious for eating their eggs and fry” qualitymarine.com: “you can remove the item they were laid on as the parents are known to eat their own eggs!” |
| pH | aqueon.com: “pH is not critical, but ideally should be between 7.0 and 8.4.” ornamentalfish.org: “pH: 6.5-8.5” |
| Swims | aqueon.com: “Goldfish are naturally bottom feeders” |
| Diet | aqueon.com: “Goldfish are omnivores, feeding largely on crustaceans, insects and plant matter in the wild.” |
| Substrate | aqueon.com: “Goldfish like to forage in the substrate, so avoid jagged or crushed glass gravel.” ornamentalfish.org: “The tank should also have aquarium gravel or sand, and ideally live plants present.” |
| Feeding | aqueon.com: “feed only what they can consume in 2 to 3 minutes, once or twice a day.” ornamentalfish.org: “Goldfish should only be fed what they can eat within a few minutes, once a day.” qualitymarine.com: “A specialized goldfish flake or pellet is a good place to start, and then supplement that with live or frozen bloodworms, brine shrimp, and mysis” |
| Lifespan editor decision | ornamentalfish.org: “There are many reports of fish living 6-8 years and some rare reports of up to 20 years or more.” qualitymarine.com: “a lifespan of about a decade, but can live twice that long under great care!” |
| Long fins editor decision | ornamentalfish.org: “To avoid injuries to long fins or delicate eyes, ornaments or artificial plants with sharp or very rough edges should not be selected.” |
| Hardness (GH) editor decision | ornamentalfish.org: “General hardness: Medium-hard (8-18°dH)” |
| Carbonate hardness (KH) | ornamentalfish.org: “Carbonate hardness: Medium-hard (5-15°dkH)” |
| Telling males from females | ornamentalfish.org: “Males develop tubercles (white spots) on their gill covers and pectoral (front) fins. Females have deeper bodies compared to males.” |
| Male:female ratio | ornamentalfish.org: “It is more likely to occur if males and females are kept in a ratio of 2:1 (males: females).” |
| Mature tank only | ornamentalfish.org: “Aquarium is cycled and ready to receive fish.” |
Editor decisions (8)
- Aqueon 60–74°F, Ornamental Fish 59–73°F, Quality Marine 67–73°F, Wikipedia 68–72°F; 65–74°F suits fancy goldfish.
- Quality Marine 6–7 in, Ornamental Fish about 8 in. Fancy goldfish typically reach 6–8 in.
- Wikipedia and Aqueon say 10 gallons per fish, Quality Marine 40. We use the common modern guideline: 20 gallons for the first fancy goldfish plus 10 for each extra.
- Ornamental Fish 6–20 years, Quality Marine 10–20 years.
- Most fancy varieties (fantails, orandas, ryukins) have long fins; Ornamental Fish warns about injuries to them.
- Ornamental Fish: medium-hard 8–18 dGH.
- Peaceful, slow-swimming fish.
- Hardy, but large tank needs and heavy waste make them a poor 'first fish' despite their reputation.