Last Updated: February 28, 2021
Common goldfish are just that: common. They are found as prizes at fairs and carnivals as well as in feeder tanks at most pet stores. They are hardy fish but often overlooked by people looking for pet fish because many people don’t see them as very exotic or unique. However, common goldfish make exceptional pets and tank mates to other peaceful fish. They can be playful and learn to recognize the person who feeds them, even begging at the top or front of their tank when mealtimes come. Keep reading to learn more about the humble, common goldfish.
Quick Facts about Common Goldfish
|Species Name:||Carassius auratus|
|Color Form:||Orange, white, yellow, red and white, black and red, yellow and black, other combinations of these colors|
|Diet:||Pellets, flakes, gel food, live food, frozen food, roughage|
|Minimum Tank Size:||5 gallons or 3-4x the length of fish in tank length|
|Tank Set-Up:||Filter; Bare bottom, aquarium sand, or large smooth rocks; Goldfish-friendly plants; Smooth aquarium décor and hides|
|Compatibility:||Other peaceful freshwater fish that cannot fit into the goldfish’s mouth|
Common Goldfish Overview
Common goldfish are a great choice for the new fishkeeper due to their hardiness in poor water conditions and temperature extremes as well as their widely available food and care supplies. There is a misconception that common goldfish don’t live very long lives, but with appropriate water quality and diet, they can live up to 20 years. The oldest common goldfish on record lived to be 43 years old! They come in a wide variety of colors, and while the basic orange-gold color they most commonly sport may seem boring, watching their shimmery scales darting around an aquarium can be very aesthetically pleasing.
Common goldfish thrive in both indoor aquariums and outdoor ponds and can survive temperatures from below freezing to 90º F or more. They can thrive in a large variety of aquarium, pond, and bowl setups as long as they receive routine water changes with treatments to remove toxins. They also need a high-quality, varied diet, and an environment they find stimulating, which can be anything from tank mates to various plants and decorations.
Common goldfish are scavengers and need roughage to graze on, enjoying things like arugula, romaine lettuce, and many herbs. They may even eat aquarium plants, but usually leave plants like anubias, java fern, and hornwort alone.
- Related Read: Ryukin Goldfish
How Much Do Common Goldfish Cost?
Common goldfish are sold at most pet stores for under $1 and can be up to $10 or more from online retailers, with prices usually varying based on size.
It’s important to keep in mind that even though the fish may be inexpensive, the initial setup cost of a bowl or aquarium, food, a water testing kit, and water treatments will all add to the price of being a goldfish owner. A basic setup for one common goldfish can be done for around $50 but can easily go into the hundreds for larger aquarium and filtration setups.
Typical Behavior & Temperament
The first is during breeding season when male goldfish can become relentless, chasing females to exhaustion and injury.
The second is when goldfish are put with fish that are small enough to fit into their mouths. They will eat fry, small adult fish, and other tank mates like shrimp. Providing plants and plenty of hiding spots can help reduce the risk of injury and death in both situations.
Appearance & Varieties
Goldfish come in many varieties, including fancy goldfish like ranchus, orandas, and bubble eyes. Non-fancy goldfish varieties include common goldfish, comets, and shubunkins. Common goldfish are most frequently stocked in feeder tanks, although comets may also show up in these tanks.
Common goldfish have narrow bodies and short fins, coming in a variety of colors and combinations other than solid orange. They are most often solid orange or a combination of orange and black, but can also come in shades of red, yellow, and white. They usually are no more than two colors. Common goldfish differ from comets in very few ways except comets have longer tails and fins than common goldfish. Shubunkins are similar to comets but with longer tails and a calico coloration. Shubunkins are rarely seen in feeder tanks.
How to Take Care of Common Goldfish
Below are some key points you’ll want to take into consideration when becoming a goldfish owner.
- Tank/Aquarium Size: Common goldfish can survive in just about any size bowl, aquarium, or pond that is at least one gallon, but they thrive with more space. The smaller the aquarium, the more frequent water changes will be needed to maintain water quality. Larger spaces also allow for a more stimulating environment.
- Water Temperature: While common goldfish prefer a temperature range from 65º-75º F, they can survive in a broad temperature range. They can survive below freezing temperatures if there is a hole in the ice for them to get oxygen through. In cold water, usually around 50º F, goldfish will enter a semi-hibernation called torpor. While in torpor, their metabolism drops significantly, and they will usually eat very little or nothing at all. It is important to keep good oxygen circulation in the water while goldfish are in torpor.
- Common goldfish can also survive hot temperatures of 90º F or more in deep enough water and with appropriate shade. While a heater is not required for indoor setups, it is recommended to maintain water temperature in a comfortable range. Tank pH ideally should be kept between 7.0-8.4, although goldfish can survive in pH outside of this range.
- Substrate: Small gravel is generally not recommended for goldfish since large enough pieces can become lodged in their mouths, requiring human intervention to get it out to prevent injury or death. Some goldfish keepers prefer a bare bottom set up for ease of cleaning, but aquarium sand is also an appropriate choice. Purchased river rocks can be used for indoor and outdoor setups if they are rinsed thoroughly before use and are smooth with no jagged edges to prevent injury to the fish. It is important to not source rocks or plants from local waterways to prevent the spread of parasites and disease.
- Plants: Plants like anubias, java ferns, hornwort, moneywort, and Amazon swords are not likely to be eaten by goldfish. They have an affinity for plants like duckweed, frogbit, and salvinia. Other plants can be grown from the top of the water, like pothos, tradescantia, and bamboo.
- Lighting: Goldfish require light for at least a few hours per day. Natural light is excellent if available, but it is best to not place the tank in direct sunlight as this can lead to an algae bloom. If natural light is not available, artificial light will suffice but it is important to have “lights out” to replicate natural sleep/wake cycles.
- Filtration: Filtration collects large particles floating in the water, like waste and uneaten food, but filtration systems also help grow the good bacteria needed within the tank to prevent ammonia and nitrogen buildup.
Are Common Goldfish Good Tank Mates?
When introducing new goldfish into a tank, they should be floated in the bag until the water in the bag is the same temperature as the tank they are going into to avoid temperature shock, which can be deadly. It’s generally recommended to quarantine new fish in a separate container for 2-4 weeks to prevent the spread of disease and parasites the new fish may have.
Common goldfish are generally peaceful fish and are good tank mates for other peaceful fish, like platys, danios, and guppies. Tank dividers can be beneficial if there are aggression issues with the goldfish or other fish in the tank.
When choosing tank mates for goldfish, it’s best to consider if the needs of both fish are in line with each other. For example, avoiding tropical fish with water requirements above 74º F since this would keep the water warmer than goldfish prefer. Aggressive fish like cichlids should be avoided since they will kill goldfish. There are some reports of mollies nipping at goldfish’s fins and Plecostomus fish sucking the protective slime coat off goldfish, so these should be avoided as well.
What to Feed Your Common Goldfish
Most goldfish foods are formulated with lifelong health in mind, but some fall short of meeting all dietary needs. A varied diet is recommended for goldfish, combining pellets or flakes with fruits and vegetables, especially roughage like leafy greens. When using pellets and flakes, look for high quality sinking food with minimal wheat or corn fillers containing marine proteins fish would encounter in the wild like shrimp and other fish.
Omega-One Goldfish Pellets and Northfin Goldfish Pellets are readily available, high-quality pellets. Repashy Super Gold gel food mix is another high-quality food option that requires some preparation. Frozen foods like bloodworms, brine shrimp, and daphnia are great treats for fish.
Keeping Your Common Goldfish Healthy
Keeping common goldfish healthy can be easy as long as a healthy diet is provided and water quality is maintained. It’s important to purchase a water test kit, like the API Freshwater Master Test Kit, to stay on top of water parameters like ammonia, nitrate, and nitrite levels and pH. Removing waste from the water, performing water changes routinely, and keeping the water at a comfortable temperature for your goldfish will keep them happy and healthy.
Finding a veterinarian that cares for goldfish can be challenging, so start by calling exotics and agricultural vets in the area to get more information.
If goldfish have been kept in cold water long enough to go into torpor, when they are reintroduced to warm water they will often begin attempts at spawning. This usually involves females being chased, sometimes leading to injury. As a result, separating fish, providing hiding places, or removing potentially dangerous décor may be needed. If you are looking to breed your goldfish, you will need to remove charcoal from the filter to increase the pheromones in the water.
A 2:1 male to female ratio is recommended to increase the chances of egg fertilization and around 12 hours of light is recommended per day. It may be necessary to increase feeding to stimulate egg production.
Fertilized eggs should be moved to a different tank to prevent them from being eaten. If the eggs do manage to survive with the fish, the fry will almost certainly get eaten.
Are Common Goldfish Suitable For Your Aquarium?
Who knew that common goldfish could be so complex? While it may sound like a lot, and does require some work, goldfish are a great choice for fish keepers of all levels due to their hardiness and availability. We’ve learned a lot about fish husbandry since we were kids keeping carnival goldfish in a bowl, but that just makes them more enjoyable.
Common goldfish can provide you with a sense of satisfaction and are a pleasant addition to your family or community tank. There is a level of fun and excitement testing new fruits and vegetables with goldfish and seeing their preferences and personalities come out. Common goldfish should be a long-term commitment and it’s important to remember that they are living things, not disposable short-term entertainment. They may be with your family for a decade or more, so be prepared to give them the best life possible.
Featured Image Credit: Sandra_M_H, Pixabay
An avid animal lover, Roland started this blog to help all varieties of pets and their owners on their journey to living their best lives.
- Quick Facts about Common Goldfish
- Common Goldfish Overview
- How Much Do Common Goldfish Cost?
- Typical Behavior & Temperament
- Appearance & Varieties
- How to Take Care of Common Goldfish
- Are Common Goldfish Good Tank Mates?
- What to Feed Your Common Goldfish
- Keeping Your Common Goldfish Healthy
- Are Common Goldfish Suitable For Your Aquarium?