Bubble Eye Goldfish: A Comprehensive Care Manual

Get to know the bubble eye goldfish, a freshwater species with an unusual appearance. Discover everything you need to know about keeping a bubble eye goldfish as a pet.

Bubble Eye Goldfish – Quick Facts

In a rush? Check out the quick facts about Bubble Eye Goldfish below.

Fish Info

Scientific NameCarassius auratus
Common NamesBubble Eye goldfish, Water-Bubble Eye goldfish
AppearanceSmall and gold colored like a regular goldfish. The main difference is the large sacs of fluid resembling bubbles around the eyes. They also lack a dorsal fin.
DifficultyCaring for bubble eye goldfish is difficult because they need a specialized environment and strict water conditions and a lack of sharp objects.
DistributionThe bubble eye goldfish is a domesticated goldfish that is distributed worldwide. It is originally from China.
LifespanThe average lifespan of the Bubble Eye goldfish is 5-10 years.
ShoalingYes, bubble eye goldfish are a shoaling fish.
TemperamentBubble eye goldfish have a gentle temperament.
Keep in Groups ofAs many as you like. As long as they all have enough room in the tank.
Tank MatesOther goldfish species, other peaceful slow moving species.
DietOmnivorous; will eat high-quality flakes, sinking pellets, daphnia, bloodworms, tubifex worms, or brine shrimp.
LengthBased only on the information above, the length of the bubble eye goldfish is 2-3 inches.
Sexual DimorphismMale goldfish are usually larger than female goldfish. Male goldfish are usually more colorful than female goldfish.
Breeding DifficultyThe fluid-filled sacs under the eyes make it harder for the males to find the female and the female to find the spawning medium, making breeding bubble eye goldfish difficult.

Water/Tank Recommendations

Water TypeBubble eye goldfish are a freshwater fish, but they can tolerate slightly brackish water.
Water TemperatureThe preferred water temperature for bubble eye goldfish is 18-22°C (65-72°F).
Water pHThe ideal water pH for bubble eye goldfish is 6.5 to 7.5.
Water HardnessThe ideal water hardness for bubble eye goldfish is 5 to 19 dH.
Tank sizeThe minimum tank size for bubble eye goldfish is 10 gallons. The recommended tank size is 20-30 gallons.


Bubble Eye Goldfish are a unique freshwater species to consider for your tank. They have a few specific requirements that you must be aware of, but once you get the hang of it, these fish will offer your tank something that no other species will.

The neat thing about these fish is their distinct appearance. Their heads have large fluid sacs around their eyes! This makes them stand out in any aquarium, more than almost any other fish!

In this guide, we go over everything you need to know about Bubble Eye Goldfish. By the time you’re done reading all of our recommendations, caring for them will seem like second nature.

About Bubble Eye Goldfish

Bubble Eye Goldfish are easily one of the most unique species to keep in your tank. With their large sacs of fluid around their eyes, they look like little aliens!

The goldfish has a long and interesting history with humans. The fish were originally bred over 1,000 years ago in China as pets for royalty. However, people soon became interested in these odd-looking goldfish, and developments in fish farming and home aquarium technology soon gave everyone the means to keep them.

The Bubble Eye Goldfish is a unique breed of goldfish that is much rarer than the standard variety. It also has some much stricter requirements, meaning it is not great for beginners.


The most obvious feature of the Bubble Eye goldfish is its large, fluid-filled sacs that surround each eye. While some fish have smaller orbs no larger than a pea, others have sacs much larger than that!

The size and shape can vary from fish to fish. Some might even be asymmetrical. These bubble eyes are full of transparent gel or oil, which is thought to provide protection against injury and environmental changes.

Aside from the bubble eyes, these fish are much thicker than a standard goldfish, and they also lack a dorsal fin.

Their Length

The average length of a bubble eye goldfish is 2-3 inches, which makes them one of the smaller kinds of fancy goldfish.

This size makes them easier to care for and keep in an aquarium than their larger counterparts.

However, the size can vary based on any number of factors.

Fish kept in small environments or with a poor diet are less likely to grow larger than those raised properly.

This is true of all fish.

Note: The depth of the body of this fish is half the size of its length on average, meaning this fish looks quite bulky despite being relatively small.


The lifespan of a bubble eye goldfish is usually between 5 and 10 years.

There are reports of some living longer than this, but it’s not common. If you want your fish to live as long as possible, you must take excellent care of them and provide the best possible environment.

Note: The lifespan of a bubble eye goldfish can be affected by how you raise them. Interestingly enough, if they’re kept in small bowls during their early years this will have a negative impact on their ultimate life expectancy.

Sexual Dimorphism

It is not easy to tell the difference between male and female bubble eye goldfish. The main way is by looking at their size; males tend to be a bit larger than females, and more colorful.


The ideal tank is a large aquarium that’s at least 20 gallons in volume (30 gallons if you plan on keeping more than one). This gives the fish room to swim, and allows for plenty of plants.

You can house bubble eye goldfish with other peaceful species as long as they are not fast swimmers! Some good potential options are:

Note: It is very important that you have no sharp decor in your tank. The bubbles on these fish can sometimes get punctured, causing a lot of problems. If a bubble pops, it may eventually regrow, but it is better to avoid this problem in the first place.

Caring for Bubble Eye Goldfish

All the information you need to care for your Bubble Eye goldfish is in this section.

Make sure there is nothing in the tank that could pop the bubbles on these fish. This includes driftwood, rocks, sharp corners, sharp plants etc.

You also need to be careful which species to keep as tank mates for this fish. Fast swimming fish can injure your bubble eye goldfish by hitting them as they swim. Similarly avoid any fish that might mistake the bubbles for food.


The ideal diet for a bubble eye goldfish is made up of a mix of commercial foods, live fish food such as brine shrimp and daphnia, and vegetables.

Bubble eye goldfish will eat pretty much any type of live or frozen food you give them. They also like bloodworms and small pieces of meaty foods. Again, they are omnivores so feel free to experiment with different kinds of dry flakes and pellets when it comes to dry foods.

How Often & How Much to Feed Them

To keep your goldfish healthy, you’ll need to feed them a proper diet. This means high-quality foods that are formulated specifically for their needs.

We recommend feeding your bubble eye goldfish 2 small meals a day. Make sure you don’t feed them too much, since this can cause issues with the fish themselves and with the water in the tank, which can become dirty due to uneaten food.

Feeding time is interesting with bubble eye goldfish because it requires some finesse! These fish have poor vision due to those sacs around their eyes which makes it difficult for them to find food in the tank (especially sinking pellets). For this reason, you should provide floating flake or pellet food unless you want to spend your feeding time having fun trying to help your fish find their food.

Possible Diseases

Something to note with most fancy goldfish types is swim bladder disease. This illness occurs when the swim bladder of your fish gets compressed, which can happen from over-eating, eating too quickly, or even eating something they shouldn’t. For example, this could be caused by tiny pieces of food that get stuck inside their intestinal tract causing them discomfort over time.

It causes them to float oddly in the water because they cannot hold themselves up normally with gas in their swim bladder. If left untreated for too long (or if untreated at all) it can lead to death.

Tank Setup

The most important thing to consider when setting up your Bubble Eye goldfish tank is their need for water that’s free of sharp objects.

This means you should avoid gravel, rocks, and driftwood in their aquarium. This is because the fish can get injured if they rub against these items while swimming around the tank.

Instead, use a smoother base material like sand or pebbles. Sand is often preferred because it makes it easier for them to find food (flakes will settle on top of sand as they sink). You can even use aquarium carpet plants! Whatever you choose, keep things smooth and soft so that there are no dangers lurking in the water.

A good way to ensure this is by having soft plants grow throughout the tank as well. Plants soften everything and make life more comfortable for your bubble eye goldfish.

The ideal tank setup for these fish should be large and spacious with plenty of room to swim. A 20 or 30-gallon aquarium is usually sufficient, but larger ones are always better if you have enough space. Add a sand substrate at the bottom and add some plants (like java moss), and other decor as well.

Aquarium Size

The minimum tank size for bubble eye goldfish is 20 gallons. The recommended tank size is 30 gallons, but you can keep more in a larger aquarium (and we recommend it).

The reason why they don’t need as much room compared to other fish species is their slow movement and their naturally calm temperament. They spend most of their time hiding out at the bottom of the tank.

Note: However, you should always provide enough space for all of your fish in the aquarium. These are shoaling fish that prefer to be around others and like having plenty of room to swim.

Water Conditions

Due to the unique eyes of this fish, the water conditions should be carefully monitored.

The most important thing is achieving a stable pH level. A slight amount of alkalinity can help prevent eye infections. Most breeders recommend neutral water for best results as well. Anything too acidic can cause irritation to their large bubble-like eyes (which doesn’t sound very fun).

Bubble Eye Goldfish need extremely clean water, so regular tank maintenance and frequent partial changes are needed to keep these fish comfortable. You might even have to invest in an algae eater if your filters don’t catch all the light debris floating around!.


Bubble eye goldfish prefer a slightly more acidic water pH of 6.5 to 7.5, so keep this in mind when choosing filtration equipment and performing weekly partial water changes.

Note: It’s also important to make sure you have the right kind of filter for your tank size and species compatibility (this is true for all aquarium fish). Allowing high levels of ammonia or nitrate into their environment could affect the health of your bubble eye goldfish.


The preferred water temperature for bubble eye goldfish is 18-22°C (65-72°F).

This should be fine if you’re starting with a freshwater tank, but this species can also withstand slightly brackish waters too. For example, they can live comfortably in waters that are as low as 5 ppt.

Keeping the tank temperature within this range is important because it will help to ensure that your fish are healthy and stress-free. Too cold of a water temperature can cause illness and disease, while too warm of a temperature can lead to high levels of ammonia in the tank (which is obviously very bad for your fish).


The hardness of the water is an important element to consider when caring for bubble eye goldfish. These fish do best in water that’s on the softer side, as opposed to very hard waters.

Water hardness should be between 5 and 19 dH.

Note: Hard water is sometimes recommended for fish that have swim bladder disease. However, there’s no scientific evidence of this being accurate.


The filtration system in your tank is an essential part of your aquarium setup, and it’s just as important with bubble eye goldfish.

These fish produce a lot of waste that needs to be cleaned out regularly. To do this, you’ll need powerful filters that can handle the extra load.

Luckily, most standard hang-on-back or canister filters will fit the bill nicely (as long as they have sufficient power).

Aquarium Plants

There are a number of different aquarium plants that you can use to decorate your bubble eye goldfish’s habitat. However, they do require some specific attention when it comes to the plant species you choose.

Generally speaking, most plants will not cause any issues for this species as long as they don’t have any sharp parts to them. That said, certain types do have sharp leaves or stems and should be avoided!

Some common aqua plants such as hornwort and water sprite should be fine. But avoid plants like Amazon swords that have pointy sections.

Behavior and Compatibility

Active and curious, the Bubble Eye Goldfish is one of the most popular community fish around. They’re quite playful and love to explore their surroundings.

However, they are prone to being bullied by more aggressive or larger species. This can result in injury (especially if you don’t have a spacious tank). Always choose peaceful fish that are on par with their size as far as aggressiveness goes.

Bubble Eye Goldfish work great in groups of six or seven fish, but be careful about overcrowding your tank with these creatures because it can lead to problems among the group.

How Many to Keep Together

As mentioned earlier, bubble eye goldfish are a shoaling species. This means that they do better when in the presence of other fish of their kind.

In fact, most aquarists recommend keeping at least half a dozen together for ideal socialization and health reasons! More than that is even better if you have adequate tank space.

Remember, these are slow-moving fish with no protection from sharp objects. They need safety in numbers to reduce their risk of injury.


These fish have a gentle temperament and are peaceful. They’re not going to fight with other non-aggressive species or disturb any live plants in the tank.

Tank Mates

The missing dorsal fin is a big drawback in terms of the swimming ability of the Bubble Eye goldfish. This is one of the reasons why you need to be very selective about what species you place with them. Any fish that can move significantly faster than your bubble eye goldfish (which is most of them) is a potential hazard to their bubble eyes.

The best option would be other bubble eye goldfish. However, even if you have an ample amount of space in your aquarium, don’t go overboard and keep too many of these together!


Bubble Eye goldfish can be difficult to breed as they don’t spawn easily. Despite the female being able to lay roughly 1000 eggs at a time, only a few of them will manage to survive and grow into more fish.

Are Bubble Eye Goldfish Fish a Good Choice For Your Tank?

As you can probably tell from the information above, caring for Bubble Eye goldfish is more complex than your average aquarium fish.

While we’re a fan of these unusual freshwater creatures and would recommend them to other aquarists who are up for this challenge, we don’t think everyone should keep them in their tank.

The main reason why is because of the extra maintenance that goes into keeping this species alive and healthy.


Bubble eye goldfish have a lot of things going for them, but we’ll start with their looks. There are many beautiful fish out there!

The distinct and large “bubbles” surrounding their eyes give these fish an interesting look that people love. You can see this from above or below, making them a nice addition to any tank setup.


The main drawback of owning bubble eye goldfish is that they require a very specific set up to thrive.

If your fish has bad genetics or lives in subpar conditions, it could result in serious health problems. Many owners have had to put down healthy looking fish with missing eye bubbles due to infection.


Caring for goldfish is a rewarding and fun experience that can last you a lifetime. There are so many different types of these fish to choose from!

With the information in this guide, you’ll be able to provide excellent care and keep your new bubble eye goldfish happy and healthy.

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