Fantail Goldfish 101: Care, Size, Lifespan & Tank Mates

Fantail goldfish are a popular and gorgeous freshwater fish that are great for beginners and experienced owners alike. Their long flowing fins are a sight you need to see!

But even though these fish are very low-maintenance, there are a few aspects of their care that can be a bit tricky.

This guide will teach you everything you should know about Fantail goldfish care. We cover tank mates, size, lifespan, diet, and much more!

Species Summary

Known for their elegant fins and regal appearance, the Fantail goldfish is one of the most popular species in the pet trade. A good option for beginners, these fish are quite hardy and can do well in the right conditions.

These freshwater fish are not found in the wild, and are the simplest kind of fancy goldfish. Like other Fancies, these fish are a product of selective breeding techniques from hundreds, if not thousands, of years ago. Their closest living relative is the carp, but Fantails are very distinct in their own right!

Readily available at most pet stores around the world, these fish can add a ton of beauty to your tank. However, they require well-maintained environments to truly thrive.

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Fantail goldfish have several standout physical traits that contribute to their popularity. The first one you’ll notice is the egg-shaped body. They do not have the slim torpedo-shaped body of a standard goldfish.

Their bodies are quite bulbous, resulting in a somewhat bloated appearance. Believe it or not, the unique shape of the body actually limits space for their organs. As a result, they are prone to a couple of diseases (more on that later).

Fantail goldfish in a freshwater tank

Another defining characteristic is the double tail fins. Rather than a simple forked shape, the caudal fin splits into four lobes. From above, it creates a triangle shape. But from the sides, it looks like a flowing fan.

Fantail goldfish have a double anal fin too. However, the dorsal fin is singular. It’s tall and arched, stretching down to the base of the tail.

The scales of the Fantail goldfish can be metallic or nacreous. Plus, they come in a wide range of colors. Orange, yellow, and red are the most common. Though, you can also find pure white, black, metallic blue, and calico!

Author Note: As the most basic kind of Fancy goldfish, don’t expect to see any extreme traits beyond what we’ve described above. Some fish may develop telescoping eyes after six months of age, but sellers will typically rename them once the eyes start to develop.

Average Fantail Goldfish Size

The average Fantail goldfish size is between six and eight inches in length. This measurement is from the nose to the tip of the tail fin. 

A large portion of that size measurement actually comes from their expansive fins. The bodies of a Fantail goldfish are usually smaller and can fit nicely in the palm of your hand.

Buying your Fantail from a reliable seller that practices ethical and smart breeding will usually result in your fish growing to be on the larger side of that size range.


The typical Fantail goldfish lifespan is somewhere between five and ten years. If you want your Fantail to reach the upper end of this range, you’ll need to provide them with top-notch care.

Author Note: This species is quite hardy, but they are prone to some health issues that could shorten their lifespan. While there is an element of luck involved, most health problems are avoidable with proper care and good tank maintenance.

Fantail Goldfish Care

Fantail goldfish care is pretty simple, and something that most beginners can handle without a problem. If you’re thinking about getting one of these fish for yourself you have a lot of fun ahead of you!

That said, they do have distinct care requirements that you’ll need to be aware of. Like other types of goldfish, these critters will not survive in the typical water conditions of tropical fish! They require cooler environments built around their safety.

Here’s some information you can use to keep your Fantail goldfish happy and healthy.

Tank Size

Let’s start with the size of your aquarium.

Fantail goldfish can get reasonably large, but they’re not powerful swimmers. Thus, they don’t need an oversized tank to stay healthy.

We recommend providing a tank size of 10 to 20 gallons per fish. If you can go up to 30 gallons per fish, that’s even better!

Author Note: Fantails are also a good fish to consider for outdoor ponds. Many owners keep them in backyard garden ponds of 180 gallons or more.

Water Parameters

As a “designer” fish, Fantails do not appear naturally in the wild. This means we have no baseline to model tank conditions after like many popular tropical species.

That said, we do have information about the goldfish’s most closely related cousin, the wild carp. Most aquarists will look to the crucian and Prussian carp for inspiration.

These fish live in slow-moving lakes and rivers. They come from higher altitudes, such as mountain rivers and tributaries. As a result, the waters are usually on the cooler side and have a more neutral pH balance.

  • Water temperature: 65°F to 80°F (around 73 to 74 degrees is ideal)
  • pH levels: 6.0 to 8.0 (aim for neutral)
  • Water hardness: 4 to 20 dKH

In order to maintain these parameters and keep their tank consistent, you’ll need to get an aquarium test kit. This will allow you to check on the state of the water and prevent any unwanted shifts that could harm your Fantail goldfish.

What To Put In Their Tank

A natural and serene tank environment is best for Fantail goldfish. You should model your tank after a calm mountain stream!

Start with a layer of a soft sand substrate. Fantail goldfish venture to all corners of their environment, and they even like to dig every once in a while. Large pebbles or chunks of gravel could scratch them, so stick to sand to be safe.

Next, you can add rocks, driftwood, and plastic decorations. Keep things simple! These fish need some decorative items for shelter in case they want to hide.

Also, make sure that there are no sharp edges. These fish are very delicate!

Author Note: Make sure you provide plenty of open swimming space. Don’t overcrowd the habitat.

Add a couple of floating and anchored plants. These goldfish particularly enjoy things like hornwort. However, anubias and java fern work great as well.

For equipment, a standard filter and lighting rig is a must. Fantails can produce a lot of waste, and this is especially true if you have a group of them. Because of this, make sure that your filtration system can handle the bioload of the tank efficiently (here are some great ones to consider)

Additional features like air stones and pumps are always welcome. They’re not necessary. But, they can enrich the environment even further by infusing oxygen into the water.

Potential Diseases

Fantail goldfish are not immune to health problems. They can suffer from all of the same diseases as many other freshwater fish.

Always keep an eye out for ich, bacterial infections, and fungal problems.

A healthy Fantail goldfish swimming

Fantails are at high risk of suffering from swim bladder disease. Typically, constipation is to blame. Their compacted organs can make it difficult for the fish to process food. The condition will affect their buoyancy, causing them to turn upside down or have trouble swimming.

There are several over-the-counter treatments for swim bladder disease. However, the easiest thing to do is avoid it altogether by managing your fish’s food intake (more on that in a bit).

Another common health concern is fin rot. This bacterial disease can eat away at those gorgeous double fins. Generally, fin rot is easy to treat with antibiotics and quarantine.

Author Note: Monitor the tank’s conditions regularly to decrease the chance of these diseases affecting your Fantail goldfish. It’s very important to make sure that ammonia and nitrate levels are undetectable to prevent stress-related health issues.

Also, change at least 25 percent of the water volume every week.

Food & Diet

Fantail goldfish are not picky when it comes to food. They are opportunistic omnivores that will consume just about anything they can get hold of.

With all that said, feeding a Fantail goldfish is trickier than one would think. Because of their propensity for developing digestive problems, you have to adjust their diet accordingly.

Stick to high-quality foods packed with nutrition. Everything should be easy to digest to avoid swim bladder disease and indigestion.

You could provide dry flakes or pellets, but we recommend sticking to live or frozen foods instead. Foods like brine shrimp, daphnia, and bloodworms offer the most bang for your buck in terms of nutrition. You can feed your fish less without having to worry about deficiencies.

For plant-based foods, try high-fiber snacks like lettuce, blanched peas, and zucchini.

Author Note: Feed your fish two small meals a day. Only provide enough food that they can eat in two minutes. They will still look hungry, but two small meals will be more than enough to keep them healthy!

Behavior & Temperament

Aggression is not an issue at all with Fantail goldfish! These fish are naturally quite peaceful and mellow.

Throughout the day, your Fantail will swim around the tank minding his or her own business. They may wriggle their way through plants, dig for food in the substrate, or interact with others.

Fantails are rather social fish. They don’t shoal, but you may see them group up and explore the tank together.

Tank Mates

Choosing Fantail goldfish tank mates can be very tricky. They’re not aggressive in any way, but they can become the target of bullies very quickly.

This is because Fantails are not strong swimmers. They can’t escape rowdy species or fin nippers. To avoid stressing your Fantail out too much, keep them with calm and peaceful tank mates.

Steer clear of any aggressive or even semi-aggressive fish. Also, avoid fast-swimmers or fin-nipping species that could damage those gorgeous flowing fins.

Here are some good tank mates that can coexist with Fantail goldfish:


Fantail goldfish breeding is very simple. Like other goldfish, they are prolific breeders that can lay thousands of eggs at once!

They do require pristine conditions to start spawning, so it’s a good idea to set up a separate breeding tank.

Create the same living conditions as the primary tank. But, include several fine-leaf plants or spawning mops for the eggs to cling to. It’s also a good idea to start at a lower temperature.

You can breed Fantail goldfish in groups or bonded pairs. Whatever the case may be, add your fish and slowly raise the temperature about three degrees per day. Don’t go above 75 degrees Fahrenheit.

Eventually, the fish will start spawning. The male will circle the female to start the process. Females will scatter eggs all over the tank. If you added plenty of plants and mops, those eggs should stay safe.

Either way, it’s important to remove the parents once the spawning process is over. These fish do not exhibit parental instincts and will eat the eggs if given the chance.

The eggs will hatch in about five to six days. After a few more days of snacking on their egg sac, the fry will become free-swimming. At that point, you can supply some powdered food, freshly hatched brine shrimp, and infusoria. High-protein foods are best, as they can help these young fish grow quickly.            


Fantail goldfish care is something that anyone can manage. As long as you’re familiar with their basic requirements and stay consistent, these fish should thrive!

Let us know if there’s anything else you’d like to learn when it comes to these fish. We’re here to help!

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