skip to Main Content

Best Aquaponics Goldfish: Single or Twin-Tailed?

Best Aquaponics Goldfish

We may earn compensation from the products mentioned in this post. See our Affiliate Disclaimer.

Goldfish are known to be an ideal fish species to keep as pets. They’re pretty, and watching them swim around in a tank can be therapeutic. But more than that, goldfish can be excellent fish to use in aquaponics. They come in different varieties that can adapt well when raised in an aquaponics system. Surprisingly to many people, not all goldfish are the cute and tiny ones in the round fish bowl you may have had growing up. Some breeds can actually grow relatively large and have a hearty appetite. But with multiple species to choose from, selecting the best aquaponics goldfish for your garden may not be as obvious of a decision as it may appear on the surface.

With so many species available, it can be hard to choose which goldfish to use in aquaponics. But know that the best aquaponics goldfish belong to either of the two categories:

  1. Single-Tail Goldfish
  2. Twin-Tailed Goldfish

In this article, we will discuss the two groups and provide examples for each to help you choose the best goldfish for aquaponics gardening.

Single-Tailed Goldfish

Single-tailed goldfish are aptly named because they have a single tail, also known as the caudal fin. When it comes to appearance, this group of goldfish has longer bodies, and they can grow large, around 12 inches or longer. 

Single-tailed varieties are athletic and fast, making them suitable in ponds or huge aquariums. They’re also extremely hardy that they can withstand harsh outdoor temperatures. Because of these characteristics, they are the best choice for beginners and for those thinking about having an outdoor aquaponics system.

The common single-tailed species include:

  • Common goldfish
  • Shubunkin
  • Comet

Let’s take a look at some of these species in more detail.

Common Goldfish

Common goldfish are readily available in many pet shops, and it’s the kind of fish that a lot of people would house in a bowl. Raised in captivity, this fish displays that iconic golden color characteristic to the typical goldfish people would imagine. But when in the wild, some appear silvery while others are dull bronze.

If placed in your aquaponics tank, it can grow to six inches. When in a pond, they can grow to as much as 10 inches.


The comet breed is another popular choice of goldfish. It can look like a common goldfish, but the difference lies in the tail.

Common goldfish usually have short caudal fins. On the other hand, comets have it much longer, giving it that flowy effect and making it a beauty to behold.

Comets come in orange, white, and yellow colors while others have patterns like orange blotches. And like the commons, comets can grow large and reach the same length.

If you want to add comet goldfish to your tank, click here.


The standard Shubunkin or American Shubunkin can easily be mistaken for the comet. Still, one can tell them apart by its calico pattern. As with most goldfish breeds, the shubunkin can boost your tank’s appeal with its vibrant colors and patterns. They can come in blue, white, black, and orange.

Another subvariety of the shubunkin is the London Shubunkin, which can look more like the common goldfish. If you want to add a dramatic flair to your tank, you can go for the Bristol Shubunkin, which has heart-shaped tails adored by many.

If you’re interested in keeping shubunkin goldfish for your aquaponics tank Click here.

Now that we have examined some of the single-tailed varieties of goldfish, let’s take a look at the twin-tailed group.

Twin-Tailed Goldfish

Also known as fancy goldfish or double-tails, this goldfish breed brings that extra appeal in tanks and ponds. They have ornate fins and other remarkable features that make them unique, sought-after, and pricier.

Double-tailed goldfish have rounder bodies compared to single-tails and are not much of active swimmers. They tend to produce a lot of waste, quickly spiking the ammonia levels in your aquaponics tank. They are sensitive to poor water quality, so you will need to have heavy water filtration in your system to keep their water clean. 

If you plan to keep fancy or twin-tailed goldfish, consider the kind of environment they are in. Twin-tails thrive better in an indoor environment rather than an outdoor one. Below are three varieties of twin-tailed or fancy goldfish that are generally hardy and great for beginners as well:

  • Fantail
  • Ryukin
  • Lionhead


Fantail are generally a hardy variety of the twin-tail group as they can survive even when kept with single-tails. However, if you plan on doing this, make sure you observe your fish and ensure that the twin-tails can eat enough.

Do you need to add fantail to your system? Click here.


For a more exciting appeal on your tank, you can keep a ryukin goldfish. This breed comes in various colors, including calico, white, red, and orange. The most expensive ryukin varieties have long, flowing fins. Ryukin may be a fancy goldfish, but beginners can keep them without problems.

Are you interested in learning more about the ryukin? Click here.


Lionheads have a somewhat different body type than most goldfish. They lack dorsal fins and have short fins. Surprisingly, this type of twin-tail is hardy and active. Some people even had success keeping them outside in winter. That said, you can choose a lionhead if you intend to have an outdoor aquaponics setup.

Choosing Between Single-Tailed vs. Twin-Tailed Goldfish

Any kind of goldfish group can be great for your aquaponics set up. They not only add beauty but also serve their purpose in your artificial ecosystem. Before you decide which type of goldfish to get for your aquaponics, consider the following factors:

  • Cost
  • Lifespan
  • Breeding
  • Feeding habits


Fancy goldfish tend to be pricier than the single-tail goldfish because of their unique characteristics. Most of them are sold by private owners and may not be readily available in pet stores. If you want a simple aquaponics system, then keeping common goldfish, rather than a fancy one, will suffice.

Temperature Requirements

Sturdy single-tail types can do well in fluctuating temperatures. A heater may not be necessary in winter as these fish can survive, as long as the water doesn’t freeze. For this reason, single-tail breeds can be an excellent choice for an outdoor aquaponics system.

In contrast, fancy goldfish are better suited for indoor setups or in areas with mild climates. If winter isn’t that harsh, they may still need to be moved inside, unlike the single-tails.


If you want a goldfish that can live really long, the single-tail goldfish like common and comets, are the best option. They can live for as long as 20 years – that means they can outlive some dogs and cats.

The same thing cannot be said of the fancy goldfish though. This group tends to have a shorter lifespan. Even with proper care, they are only able to live for five to ten years on average. This is because fancy goldfish are selectively bred, which renders them genetically fragile.

Issues When Mixing Goldfish Groups

Single-tail goldfish can become rambunctious and can nip at twin-tails when they’re in one tank. The twin-tails may not get enough to eat as well since they are not as fast as single-tails during feeding time. As a result, the ones that repeatedly miss out on feedings will eventually become stressed.

Another problem with mixing two types of goldfish could happen during mating. When the male will go after a female, which happens to be a slower twin-tail with poor eyesight such as the bubble-eye breed, it can be distressing. In this case, close monitoring may be required to make sure your fish won’t get hurt.

Generally, if you plan to keep single-tails and twin-tails in one tank, keeping a close eye on them is necessary. If you don’t want to take the risk of losing fish after fish due to stress, make sure you choose only breeds that belong to the same group.

Conclusion: What’s The Best Aquaponics Goldfish?

There are hundreds of goldfish varieties that are tempting to keep for your aquaponics garden. These fish have a striking beauty that quickly captures anyone’s attention. But when selecting the best breed of goldfish, you have to consider certain factors that can affect the success of your overall goldfish aquaponics system.

Besides cost, lifespan, and the temperature requirements previously mentioned, choosing the best goldfish aquaponics will also depend on your experience and the type of system you want – whether outdoor or indoor. 

If you want a hardier type of goldfish that can be raised outdoors without problems, the more resilient single-tail varieties will be best. If you are a more experienced fish handler, then keeping fancy types shouldn’t be a problem.

The Campbells love finding sustainable and fun ways to increase their independence from traditional brick and motor supermarkets. Aquaponics provides a full lifecycle food source for families and a great hobby. #aquaponicslifestyle

Back To Top