Fantail Goldfish 101: Care, Tank Size, Food and More…

The Fantail Goldfish is a fantastic beginner fish.

Their iridescent colors and elegant, trailing fins will leave you in awe.

Whether you have a 20 gallon aquarium or a backyard pond, this fish is quite versatile and can thrive in either set up. They eat a wide variety of foods and get along with plenty of other peaceful fish, whilst being very sociable with other Fancy Goldfish.

After reading this article you will have the knowledge to not only look after these fish but also to appreciate their rich history and ancestry.

Keep reading to learn everything you need to know about Fantail Goldfish…

Fantail Goldfish

Fantail Goldfish 101

Fantail Goldfish (Carassius auratus) are a type of Fancy Goldfish and are not found in the wild.

All Goldfish are direct descendants of wild carp such as the Prussian, Silver Prussian and Gibel Carp (Carassius gibelio). Because they are descendants of wild carp they belong to the Cyprinidae family along with more than 125 other types of fancy goldfish.

Fantail Goldfish are popular because of their beautiful appearance, rich ancient history and docile temperament.

They differ from other Goldfish because of their egg-shaped body, split caudal fin and elegant swimming style.

These Goldfish are hardy and beginner friendly.

You should expect to pay around $5 for each fish; however some of the rarer colors and scale varieties can be more expensive.

Key Facts:

  • Experience Required: Beginner.
  • Nicknames: Fantail and European Ryukin.
  • Color Forms: Orange, Red, Silver, Blue, Gold, Black and Calico.
  • Size: 6-8 inches.
  • Tank Size: Minimum 20+ gallon.
  • Tank Temperature: 65°F to 72°F.

  • They are beautiful
  • Eat a wide variety of food
  • Peaceful
  • Do not require a big tank
  • Can be kept with other Goldfish

  • Prone to digestive issues
  • Make a lot of waste
  • Incompatible with many plants

Fantail Goldfish Care Guide

Calico Fantail Goldfish

For the most part Fantails are hardy and low maintenance.

One key thing to watch out for is their diet.

Because they are messy eaters they can produce a lot of waste.

A larger tank will help to dilute waste production but it is still important to undertake frequent water changes.

Most Fantail tanks need to be cleaned at least once every two weeks. You should wipe the glass down to get rid of any excess algae and perform a 25% water change.

Swim bladder disease is the main issue with all Fancy Goldfish.

This issue is often due to constipation, so a common solution is to starve the fish for 24 hours, before feeding them live foods with high nutrient content. The best way to prevent this problem is to carefully monitor the type and amount of food you are feeding your fish.

Fantails are also susceptible to Ich and fungal/bacterial problems. This can be treated with over-the-counter medication. The best way to minimize these risks is to maintain water quality and properly quarantine any new additions to the tank.

The other common health problem is fin rot.

This occurs when bacteria infiltrates cuts and scrapes.

You can treat this with regular medication but prevention is better than the cure.

Make sure there are no sharp objects in the tank and maintain a high water quality.

How Long Do Fantail Goldfish Live?

You can expect your Fantail Goldfish to live for around 10 years though some have been known to live for 15 years.


In their natural habitat carp are omnivores and eat detritus, vegetation, insects, leeches, nuts and fruits, crustaceans, and larvae.

Your Fantail Goldfish will eat almost anything you give them.

There is a catch, though, as these fish are susceptible to digestive issues and can suffer from swim bladder disease.

The key is to stick to high-quality foods with lots of nutrients.

Sinking dry flakes and pellets are fine, but live food such as daphnia and bloodworms also work well due to their highly nutritious content. To provide some fiber you can feed them blanched lettuce, zucchini, peas, carrots and spinach.

You should avoid floating foods as they increase the risk of swim bladder disease because your Goldfish will gulp air whilst feeding.

Feed your Fantails twice per day.

A good rule of thumb for this is to only provide as much as they can eat in two minutes.

Because of their slow swimming they are an easy target for more boisterous fish which will also outcompete them for food. Make sure to watch them and ensure they get some food.

What Food Can They Eat?

  • Bloodworms
  • Tubifex worms
  • Daphnia
  • Mosquito larvae
  • Brine shrimp
  • Lettuce
  • Zucchini
  • Carrot
  • Peas
  • Spinach


The Goldfish are very peaceful and will not engage in any aggressive activities at all.

They are happiest in tanks with other Fancy Goldfish and often explore the tank together. Although they are not a shoaling fish, they are very social and often interact with other Goldfish by playing or following each other around the tank.

When they are happy they will explore all of the tank.

They won’t use hiding spots often but it is a good idea to have some as it helps reduce stress, especially if you have some non-Goldfish tank mates.

You will see them looking for food at both the top and bottom of the tank, often digging in the substrate, but most of their time is spent in the middle of the tank.

Habitat and Aquarium Set Up

Because Fantail Goldfish are not found in the wild, it is best to model their tanks on wild carp habitats.

Wild carp are originally from the Danube river basin with native ranges throughout the Black, Aral and Caspian Seas. They inhabit slow-moving rivers and lakes where there is abundant vegetation, not much light, and a low water-flow.

Although they are tolerant to many different water conditions, they prefer large bodies of water such as lakes with soft sediment, slow-moving water and plenty of vegetation.

They can tolerate low oxygen levels as well as low temperatures, dropping to as low as 37°F.

You will need at least a 20 gallon tank for your Fantail Goldfish. The recommended tank size may be surprisingly small given the size of the Fantail, but they are slow swimmers and do not require a large amount of space.

Just make sure the tank is rectangular and not a bowl or spherical shape.

As for water parameters:

  • Temperature: 65-72°F
  • pH: 6.0-8.0
  • Water Hardness: 5-19 dGH

Maintaining the water quality will require an efficient filtration system as Fantails produce lots of waste. If you want to you can add a pump to move and oxygenate the water, but water flow is not necessary for this fish.

You should model their aquarium from their natural environment.

For the substrate you can use fine sand or gravel.

Bright lights are not suitable for Goldfish so you should go for a soft glow of orange, blue or green instead of a harsh white light.

You should keep most of the tank empty so they have lots of space to swim.

If you want to include some plants just remember that Goldfish can dig and uproot any plants that are not firmly anchored to the gravel.

Some ideal anchored plants to include are Java Fern, Anubias, Java Moss and Amazon Sword.

Some good floating plants are Duckweed, Frog Bit, Water Lettuce and Water Hyacinth.

Tank Parameter Requirement
Minimum Tank Size 20 Gallons
Tank Type Cold Freshwater
Temperature 65-72°F
pH 6.0-8.0
Hardness 5-19 dGH
Flow Low
Substrate Sand or gravel

What Size Aquarium Do They Need?

You should have at least a 20 gallon tank for a Fantail Goldfish. An additional 10 gallons should be added for each individual you add to the tank.

Fantail Goldfish Appearance

Carassius auratus

Fantail Goldfish have a mesmerizing appearance.

Their defining feature is their split caudal fin that flows gracefully behind them.

They also have an egg-shaped body which is different from the normal torpedo-shaped body of regular Goldfish. This egg-shape is caused by their wide head and short, stumpy body.

A fully grown Fantail Goldfish will normally reach 6-8 inches but some have been known to reach up to 12 inches.

Most will have regular eyes but some can develop telescopic eyes.

Their caudal fin is what makes them so attractive.

This usually distracts from the fact that their anal fin is also split, but their dorsal fin is singular. The dorsal fin is tall which makes them look bigger than they are.

Sexing the males and females is extremely difficult.

The best way to sex your goldfish is to wait until they are old enough and in breeding season (springtime). The female will appear fatter as she is carrying the eggs, but the real distinctive feature is with the males. Not only do they appear to be more colorful than the females, but they also grow breeding tubercles that look like white prickles on their operculum and head.


If the shape of this Goldfish was not beautiful enough, then just wait until you see the wide variety of colors they come in.

You can find them in:

  • Orange
  • Red
  • Black
  • Blue
  • Silver
  • Gold

One of the most popular morphs is the Calico, which is a mix of white, black and orange.

They are also available with three different types of scales:

  • Metallic: Solid color with a polished look as they are highly reflective. This scale type is the most popular.
  • Nacreous: This is a speckled look with both translucent and reflective scales. This is typical of the calico fish.
  • Matte: Very little color due to translucent and flat coloration and no reflective scales.

History and First Sighting

Goldfish cannot be found in the wild as they are descendants of wild Carp.

Prussian, Silver Prussian, Gibel and Crucian Carp were domesticated in ancient China. It is thought that the original ancestor of the Fantail Goldfish is the Gibel Carp.

Recent genetic studies found a closer phylogenetic relationship between the fantail goldfish and the Gibel Carp, as opposed to the previously thought close relationship to the Crucian Carp.

We do know that goldfish were first domesticated in ancient China, and were established in Japan by the 1500s before proliferating in Europe and America in the 1600s and 1800s respectively.

However, not much is known about Fantail Goldfish and when they were first bred.

Tank Mates

In the wild carp can be found with many other species of carp and other larger fish that reside in lakes such as bream, pike, bass and trout.

The Fantail Goldfish is a very peaceful fish so you need to find other peaceful tank mates.

They cannot be fin nippers and should be able to thrive in similar water parameters.

The first tank mate you should consider is other Fancy Goldfish. Ryukins make wonderful tank mates.

Some others you could include are:

  • Pearlscale
  • Ranchu
  • Lionhead
  • Oranchu
  • Black Moor
  • Celestial Eye
  • Platys
  • White Cloud Minnows
  • Giant Danios
  • Zebra Danios
  • Rosy Barbs
  • Hog Nose Catfish
  • Dojo Loach

You can also consider some non-vertebrate tank mates such as Ghost, Cherry and Amano Shrimp, or some snails such as Mystery and Nerite snails.

Any aggressive species should be avoided as Fantails are unable to defend themselves.

You will also need to avoid fin-nippers.

Tiger Barbs, Cichlids, Arowanas, Betta’s and Red Tail Catfish should all be avoided.

Keeping Fantail Goldfish Together

Keeping Fantail Goldfish with other Fantails is the best and safest option for tank mates.

The main thing to think about when keeping these fish together is the amount of waste that they produce, as just one individual requires a hefty filtration system.

When keeping more than 2-3 together you should invest in a dual-action filtration system, increase the tank size to dilute the waste, and invest in some plants or bottom feeders that will help to clean up the excess mess.

Breeding Fantail Goldfish

Fantail Goldfish are very easy to breed.

If you want to try your hand at breeding then you will first want to set up a separate breeding tank with pristine conditions. This will keep the eggs safe from any other fish and will make sure the breeding pair are not stressed.

Your breeding tank should be 30 gallons and should initially have the same water parameters as their normal tank.

The trick to breeding these fish is to raise the temperature day by day by 3°F, not surpassing 75°F. This replicates the water temperature at springtime, which acts as a seasonal trigger for spawning.

When mating the male circles the female before she scatters up to 10,000 eggs all over the tank. Here is the most important part. Remove the adults from the spawning tank as they will eat the eggs. They can go back into their regular tanks whilst you wait for the fry to hatch.

This usually takes 5-6 days.

Once the fertile eggs are stuck to a hard surface, in the last 24-36 hours, they will absorb their egg sac and hatch before darting to the surface to gulp air into their swim bladder. Once hatched you can feed them high-protein food such as infusoria.

At around 4 weeks old you can feed them bloodworms and crushed fresh foods.

Should You Keep The Fantail Goldfish? (Summary)

Fantail Goldfish
Other Common Names: Fantail, European Ryukin
Scientific Name: Carassius auratus
Family Name: Cyprinidae
Distribution: Captivity only
Size: 6-8 inches
Color: Orange, Red, Silver, Blue, Gold, Black and Calico
Care Level: Beginner
Temperament: Peaceful
Lifespan: 10-15 years
Minimum Tank Size: 20 gallons
Tank Mate Compatibility: Slow moving, peaceful fish

Whether you are just starting out in the fish-keeping hobby, or want to add a little variety to your aquarium, this is the perfect fish for you.

Fantail Goldfish are hardy and peaceful fish that thrive in cold water.

They eat a wide variety of foods and are compatible with lots of other fish.

Watch in awe as these beauties swim around your tank alone or in groups.

Now you know about these anciently domesticated goldfish, are you still interested in them? Let us know in the comments below…