Scientific Classification
- Scientific Name: Carassius auratus
- Common Names: Fantail goldfish, double tail goldfish
- Genus: Crucian carps
- Family: Cyprinidae
Species Overview

The fantail goldfish is an incredibly popular species in the pet trade due to its elegant fins and regal appearance. This hardy fish comes in a wide range of colors and can have either metallic or matte scales. They also have beautiful, floating double tails, giving them their characteristic egg-shaped body and comic, wobbling swimming style.
The Fantail goldfish is the starting point for almost all the breeds of fancy goldfish and is the most basic variety out there. Other fancy goldfish varieties are often built on the fantail.
Fantail Goldfish Lifespan
Fantail goldfish make wonderful pets and can provide many years of enjoyment. With proper care, their lifespan can range from five to ten years, and even up to 15 years if given the best care. Their vibrant colors and beautiful fins make them a popular choice for aquariums.
To ensure that your Fantail goldfish live a long and healthy life, provide them with a clean environment, fresh food, and plenty of space to swim. With the right care, your beloved Fantail goldfish can provide you with years of joy.
Appearance and Average Size

The Fantail Goldfish is a beautiful and peaceful freshwater fish that makes a great addition to any tank. It is bred for showing and is known for its bright colors and split caudal fin (tail fin).
The average size of a full-grown fantail goldfish is between 6 and 8 inches in length, measured from their noses to the tip of their tail fins. They typically live for five to ten years and can reach up to 10 to 12 inches in length, although this is rare.
The care level for these fish is beginner, making them a great choice for those just starting out in the fish-keeping hobby.
Fantail Goldfish Care

Fantail goldfish are a popular choice for aquariums due to their bright colors, hardiness, and ability to thrive in a wide range of temperatures. They prefer temperatures between 61°F and 77°F and a pH of between 7.0 and 8.2.
The tank should be cleaned at least once every two weeks, and the glass should be wiped down to remove any excess algae.
Food and Diet
Fantail goldfish require a varied diet to stay healthy and active. They are omnivorous, and their diet should include a combination of meat-based foods such as bloodworms, tubifex worms, daphnia, and brine shrimp, as well as plant-based foods such as lettuce, zucchini, and blanched peas.
For convenience, you can feed them dry flakes or pellets, but it is best to stick with live or frozen foods.
Recommended Tank Size
Fantail goldfish are beautiful fish, but they do require a bit of room to swim. They grow to a fair size and produce a lot of waste, so it is recommended that you start with at least a 20-30 gallon tank for your fantail goldfish.
If you are adding more than one fish to the tank, then you should add an additional 10 gallons for each fish. 10 gallons is the absolute minimum required to house a fantail goldfish, but it is best to start with a larger tank to ensure their health and comfort.
Outdoor ponds are also an option for your fantail goldfish if you have the space and resources to do so.
Proper Water Parameters
Fantail goldfish require a specific water temperature range of 65°F to 72°F, with an ideal range of 61°F to 77°F. The pH should be between 6.0 and 8.0, and the hardness should be in the range of 5 to 19 dGH.
It is important to maintain the water parameters in order to ensure the health and well-being of the fish. This includes regular water changes and monitoring of the water chemistry. With proper care, these fish can live for many years in a healthy environment.
What Do They Need In Their Tank
For the best environment for Fantail goldfish, it is important to create a natural and serene tank. To do this, try to imitate the peaceful atmosphere of a mountain stream. Start by selecting the right tank size for the goldfish to grow and thrive.
Make sure to properly set up the tank, including the right substrate, lighting, and water conditions. When picking out decorations, go for a calm, natural look with things like plants, gravel, and driftwood. With the right decorations and setup, you can create the perfect home for your Fantail goldfish.
Add anchored and floating plants. These goldfish especially enjoy things like hornwort. However, Anubia and Java ferns work well.
Standard filters and lighting installations are mandatory for the equipment. Fantails can cause a lot of waste, and this is especially true if you have a bunch of them. So make sure your filtration system can handle your tank’s bioload properly. Other items, such as air stones and shells, are also welcome.
Choosing a Substrate for Your Fish
Choosing the right substrate for your fantail goldfish is an important decision. An inert substrate, such as gravel or pebbles, is the most popular choice and is preferred by many beginners.
Sand is also an excellent option, as it is more natural for goldfish, and they can spend hours sifting through it for fun. Aragonite should be avoided as it increases the general and carbonate hardness of the water and raises the pH.
Potential Health Problems
Fantail goldfish can be prone to certain health issues. The most common health problems include goldfish ich, swim bladder disease, fin rot, tail rot, and fungal infections. Goldfish ich is a common problem and is caused by poor water quality.
Swim bladder disease is another common threat, affecting their organs and making it difficult for them to process food.
Fin rot and tail rot are caused by poor water conditions and bad bacteria in the tank.
Fungal infections are caused by poor water quality and dirty tanks.
To help avoid these possible health problems, you should ensure that your Fantail goldfish are in the best environment possible.
Behavior and Temperament
Fantail goldfish are peaceful, mellow fish that make great additions to any aquarium. They typically swim around the tank, interacting with other fish, or they may even dig in the substrate.
Fantail goldfish are social creatures and get along best with other peaceful species. While they are among the hardiest of the fancy goldfish, they should not be kept with tropical or betta fish as they may become aggressive.
Best Tank Mates
When it comes to selecting tankmates for your Fantail goldfish, it can be difficult to find the best fit. Fortunately, there are several excellent options for community tanks.
Ryukins, Celestial Eye Goldfish, Bubble Eye Goldfish, Cory Catfish, Rosy Barbs, Zebra Danios, and White Cloud Mountain Minnows all make great tank mates. Angelfish are an interesting addition too, although they require special considerations.
The most important thing is to choose tankmates that have similar water-condition requirements. With the right combination of fish, you can create a vibrant and peaceful goldfish community!
Breeding
Breeding fantail goldfish can be a rewarding experience. To start, drop the temperature of the water to somewhere between 10°C (50°F) and 12°C (54°F). Then, gradually raise the temperature by 2°C (3°F) per day until it reaches between 20°C (68°F) and 23°C (74°F).
It is important to note that fantail goldfish prefer colder water than some other goldfish species, with an ideal temperature of 70 degrees F during the day and 50 degrees F at night. To successfully breed fantail goldfish, it is best to have one male and one female in a breeding tank.
Introducing live food to the tank can also encourage them to breed. With some patience and dedication, it is possible to enjoy the sight of thousands of tiny eggs laid by your fantail goldfish!
Care For The Goldfish Eggs
It is important to breed fantail goldfish in a separate tank to ensure their safety and the success of the spawning process. When the eggs are laid, the parent fish should be removed immediately, as they do not possess parental instincts and will eat the fry. This will help to provide a safe environment for the eggs to hatch and the fry to grow without any further disturbance.
After the eggs are laid, it will take roughly 4–7 days for them to hatch, at which point the fry should be fed. It is important to note that they should not be fed before hatching, as they feed off the egg sac during this time. Once hatched, the fry should be fed one meal per day to avoid overfeeding.
Final Thoughts
The Fantail Goldfish is a beautiful and unique fish that is surprisingly hardy and well-suited for most freshwater aquariums. It is recognizable by its medium size and double/split tail fins, and it is one of the more popular or well-known breeds of goldfish. It is flamboyant, small, and relatively easy to keep, even for a beginner.
With its hardiness and attractive appearance, the fantail goldfish is an ideal choice for any fish enthusiast.
FAQs
How Big Does a Fantail Goldfish Get?
A fantail goldfish is typically between 6-8 inches in length, with its expansive fins making up a large portion of that measurement. The maximum size for a fantail goldfish is usually 8 inches; however, some pond specimens have been known to exceed that length. In terms of their final adult size, fantail goldfish are considered average, with the potential to grow up to 12 inches long.
To ensure that your fantail goldfish remains healthy and grows to its full potential, it is important to provide them with a suitable tank size, a varied diet, and regular maintenance.
Do Fantail Goldfish need Company?
Fantail goldfish are peaceful and calm species and should not be kept alone since they appreciate other varieties of fancy goldfish as tank mates. Therefore, it is best to provide fantail goldfish with a company in order to ensure they are kept in optimal conditions and live long and happy lives.
What Is the Difference Between a Fantail and a Goldfish?
The difference between a fantail and a goldfish can be easily seen in the shape of the tail fins. Fantails are a type of fancy goldfish with a forked tail or a top and bottom lobe, while regular or feeder goldfish have a single tail.
Fantails also have a short and globular bodies, while the body of a regular goldfish is elongated.
Can Fantail Goldfish Live with Common Goldfish?
Fantail goldfish are considered to be slow, clumsy swimmers, and so it is generally best to avoid keeping them with common goldfish, Comets and Shubunkins, which are much faster.
The best tankmates for Fantail goldfish are other fancy goldfish, such as Ryukins, which have similar traits.
Longer-bodied goldfish, such as Commons and Comets, should not be kept with larger, flowier-finned fancy goldfish.