Are Goldfish Hardy or Not? {8 Hardiest Goldfish Breeds}

Are you looking to get a hardy fish and are wondering are goldfish hardy or not?

Can they survive winter in a pond? Will they die?

Find out below.

Are Goldfish Hardy or Not

Goldfish are considered to be hardy fish. They have been selectively bred for centuries, resulting in various breeds with different shapes, sizes, and characteristics.

When compared to other tropical fish species, goldfish are known for their ability to tolerate a wider range of water conditions, including lower temperatures during winter.

They can adapt to different environments and survive in less than ideal conditions. Nonetheless, proper care, appropriate tank size, good water quality, and a balanced diet are still essential for their overall health and well-being.

Which Goldfish Are The Hardiest

Which Goldfish Are The Hardiest?

The hardiest type of goldfish is the common goldfish. The common goldfish are so easy to care for that they can survive even in diverse outdoor environments. While under these conditions, they can still retain their shape and bright colors.

Below is a list of the hardiest goldfish breeds.

1. Common Goldfish

The common goldfish is the hardiest type of goldfish. They are also large and can grow up to 12 to 18 inches. The standard goldfish are fast swimmers, colorful, and they can thrive well in the competition for food.

2. Comet Goldfish

They are quite similar to the common goldfish. The significant difference is that the comet fish are relatively longer and have a longer tail fin. They are mainly characterized by their fast swimming ability and their ability to cope with frigid temperatures.

3. Fantails

Fantails got their name from the nature of their extended “triple” tail. They are one of the least hardy species of goldfish. They usually have humpbacks.

4. Shubunkins

This variety of goldfish has unique colors. They actively overcome predation because of their fast swimming ability. They typically have bright colors, and shubunkins can grow as large as 12 to 18 inches.

5. BubbleEye

The BubbleEye is one of the slowest varieties of goldfish. Consequently, they are prone to predations. They are also fragile and not as hardy as others.

6. Ryukin

This variety of goldfish is quite hardy, and they form the right choice for beginners. One of the outstanding features of this variety is the noticeable hump behind their head. They also have bright colors.

7. Telescope Eye Goldfish

This variety of goldfish got its name from the nature of its eyes. It also has a natural egg-shaped body and two caudal fins. This variety of goldfish is relatively smaller in size compared to others.

8. Veiltail Goldfish

The Veiltail goldfish is arguably the most gorgeous goldfish. As much as they are beautiful, they are also very delicate. Consequently, it is best to keep them in the aquarium with enormous protection.

What Conditions Can Goldfish Survive In

Goldfish are known for their ability to tolerate a wide range of conditions, including some extreme ones. Here are a few examples of extreme conditions goldfish can withstand:

  • Cold Temperatures: Goldfish can survive in cold water temperatures that would be too cold for many other tropical fish species. Some goldfish varieties, such as the common goldfish (Carassius auratus), can tolerate temperatures as low as 40°F (4°C) or even lower.
  • Oxygen Deprivation: Goldfish have a unique adaptation known as a labyrinth organ that allows them to extract oxygen from the air. This adaptation enables them to survive in oxygen-depleted water conditions or even temporarily out of water.
  • Variable Water Quality: Goldfish are relatively tolerant of fluctuating water conditions. They can handle modest variations in pH levels, hardness, and dissolved oxygen. However, it’s important to note that consistent and appropriate water quality is still crucial for their long-term health.

While goldfish can tolerate some extreme conditions, it’s important to provide them with the best possible care and maintain stable, optimal conditions in their tank. Regular monitoring of water parameters, proper filtration, and a balanced diet will help ensure their overall well-being.

Ideal Conditions Goldfish Need

To provide ideal conditions for goldfish, it’s important to consider the following factors:

Tank Size

Goldfish require a spacious tank due to their potential size and high waste production. A general guideline is to provide at least 20 gallons (75 liters) of water per goldfish, with even larger tanks recommended for larger varieties.

Water Temperature

While goldfish are hardy and can tolerate a range of temperatures, the ideal temperature for most goldfish is between 68°F (20°C) and 74°F (23°C). Avoid extreme temperature fluctuations, as sudden changes can stress the fish.

Water Quality

Goldfish thrive in clean, well-filtered water. Regular water changes (around 20-25% every 1-2 weeks) help maintain good water quality. Monitor and maintain appropriate levels of ammonia, nitrite, nitrate, pH, and dissolved oxygen. Avoid overstocking the tank to prevent excessive waste buildup.


A high-quality filtration system is crucial for goldfish tanks to remove waste, toxins, and maintain good water quality. Choose a filter that is specifically designed for the tank size and capable of handling the waste production of goldfish.


Provide a balanced and varied diet suitable for goldfish. Feed them high-quality pellets or flakes formulated for goldfish, supplemented with occasional treats like freeze-dried or blanched vegetables. Avoid overfeeding to prevent obesity and associated health issues.

Tank Environment

Goldfish appreciate an aquarium with plenty of swimming space and adequate hiding spots, such as caves or plants. Use decorations and plants that are safe for goldfish and won’t harm their delicate fins or be ingested.

Will Goldfish Survive in an Outdoor Pond

Yes, goldfish can survive in an outdoor pond under certain conditions. Here are some key factors to consider:

  • Climate: Goldfish are cold-water fish and can adapt to a wide range of temperatures. However, extreme temperature fluctuations or very hot climates may be challenging for them. It’s important to ensure that the pond provides suitable conditions for their survival.
  • Pond Size: Goldfish require enough space to swim and thrive. The pond should be large enough to accommodate their growth and provide adequate oxygenation. As a general guideline, allow at least 10 gallons of water per inch of goldfish.
  • Filtration and Oxygenation: Proper filtration and aeration are crucial for maintaining water quality in an outdoor pond. Installing a filtration system and a pond aerator will help remove waste, debris, and maintain oxygen levels, which are essential for the goldfish’s health.
  • Predators: Outdoor ponds may attract predators such as birds, raccoons, or cats, which can pose a threat to goldfish. Consider adding protective measures like netting or creating areas of hiding spots to minimize the risk.
  • Feeding: Goldfish in outdoor ponds can benefit from natural food sources such as algae, insects, and plants. However, it’s recommended to supplement their diet with appropriate fish food to ensure they receive adequate nutrition.
  • Maintenance: Regular maintenance is necessary to keep the pond clean and balanced. This includes monitoring water parameters, performing partial water changes, and keeping the pond free from excess debris.

Can Goldfish Survive Winter In a Pond

Yes, Goldfish will survive winter in a pond, provided the pond is deep enough, doesn’t freeze solid, and appropriate measures are taken to maintain oxygen levels.

They become less active and require less feeding in colder temperatures. Monitoring water conditions and protecting against predators are important.

Some varieties may be more sensitive and require additional precautions or wintering indoors.

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Frequently Asked Questions

Do Goldfish Live Well In Cold Water?

Goldfish are cold-water fish and can live well in colder water temperatures. They are able to tolerate a wide range of temperatures, including cooler conditions. In fact, goldfish thrive in temperatures between 65-75°F (18-24°C). Cooler water temperatures can actually benefit goldfish by slowing their metabolism and reducing their susceptibility to certain diseases.

Can Goldfish Survive in Tap Water?

Yes, Goldfish can survive in tap water, but the quality of tap water can vary depending on location. Tap water may contain chlorine, chloramines, or other chemicals that can be harmful to fish. It is recommended to treat tap water with a suitable water conditioner to remove chlorine and make it safe for goldfish.

Will Goldfish Survive in a Frozen Pond?

Goldfish are unlikely to survive in a completely frozen pond. When a pond freezes over, it traps gases and limits oxygen exchange, leading to poor water quality. Additionally, prolonged exposure to extreme cold can be fatal for goldfish. It is essential to prevent complete freezing or provide alternative arrangements, such as moving them to an indoor tank or using a pond heater, to ensure their survival.

What Do Goldfish Do When It Gets Cold?

When it gets cold, goldfish become less active and their metabolism slows down. They tend to spend more time near the bottom of the pond, where the water is relatively warmer and stable. Goldfish may enter a state of dormancy or hibernation, reducing their feeding and energy requirements. This adaptation helps them conserve energy and survive in colder temperatures.


Hello, I'm Jason. I'm the guy behind I volunteer at my local fish shop and I created this site to offer tips and advice on the fish I care for.