How to care for a Goldfish


Do you want to learn how to care for a goldfish? If you are thinking of buying a goldfish as a pet, you have made a great choice, and you have come to the right place.

We present the Beginner's guide to the basic care of Goldfish. We show you step by step the fundamental knowledge to successfully take care of your goldfish.

Beginner's guide to the basic care of Goldfish

The goldfish fish They are one of the most common, popular, cheap and easy-care fish that exist. And they are excellent pets for both the enthusiasts of the aquarium hobby as for the beginners of this wonderful love of aquariums.

If you are a somewhat overwhelmed beginner and want someone to teach you how to care for a golden carp, you will love this guide about goldfish care.

Thanks to this guide for the care of goldfish you can start assembling your aquarium, and we will guide you through the basic steps you need to take care of your goldfish.

Keep reading and discover all the details on how to care for a goldfish, below.

Goldfish fish care

Goldfish or goldfish

One of the most common fish in the aquarium hobby, are the goldfish or goldfish, belong to the family Cyprinidae and they are native to East Asia.

Goldfish or goldfish

They are related to carp, but they are not equal to it, and they were domesticated for the first time from fish consumed in China more than 1,000 years ago. If you want to have more information about fish You can take a look at our category dedicated to our aquatic friends.

He goldfish, goldfish, Golden carp or golden carp are distinguished from koi tents Y common due to the absence of chins or "whiskers" at the corners of their mouths.

Through selective breeding, many varieties of goldfish are currently available, and when properly cared for, goldfish can live more than 20 years in captivity.

Golden Fish Natural Habitat

The goldfish are cold freshwater fish which are spread throughout nature and can be found in rivers, streams, lakes, ponds, reservoirs and practically in all the freshwater habitats of the planet, from temperate to tropical environments.

Goldfish have also been introduced in many parts of the world to control mosquito populations.

Types of goldfish

As a result of selective breeding, there are many different types of goldfish available today. All varieties are of the species Carassius Auratus.

Types of Goldfish

There are many types of goldfish, the common goldfish, Kite, Shubunkin, Oranda, Ryukin, Lion's Head, Telescope... to name a few.

Most goldfish are classified into one of two categories: regular or fancy. Regular fish are the kites, common Y Shubunkins. There are many more varieties of goldfish fancy.

If you can choose, it is recommended to choose the common goldfish because the characteristics of fancy fish provide problems in the internal organs as a result of their deformities.

However, if you already have some other type of goldfish, then you can take advantage that they do not grow as much as the common ones, so they do not need such a large aquarium when they are adults.

When you choose several goldfish, do not make a mixture of varieties with the common ones, since these will compete and surpass the other varieties in terms of food.

The differences between the common Carassius Auratus and the other varieties, is that the common ones are generally larger, faster, more active, need larger tanks, and are generally healthier.

Goldfish in captivity

The common goldfish, kites Y shubunkins They are excellent outdoor pond fish and are known to survive relatively cold winters.

The golden fish fancy, like orandas, ryukins and others, they can also be kept in outdoor ponds, but they are more vulnerable to predators and must be protected during winter in harsh climates.

In an aquarium, goldfish need minimum conditions that we will now see in more detail.

Choose your new golden carpín

One of the funniest parts of goldfish fish farming is getting new fish. But you have to keep in mind that it's not just about choosing a fish that you like, but it's healthy.

It is best to start with the best possible foot by buying a goldfish that is obviously not sick. If you have already bought it or have your goldfish, then you can skip this step and move on to the next point.

If you are going to buy it at your local pet store, you will have to look for fish that meet the following criteria:

    Swim actively and normally, without flotation or sinking problems. He looks cheerful and constantly moving, trying to find something to eat. It has no severe genetic defects. It is not in the same tank with sick or dead fish. You are not living in dirty water conditions that could lead to an infection. It shows no obvious signs of disease: fins that look bloody, white spots, red marks, etc.

But there is something else to watch out for ...

The type of goldfish you buy can make a big difference in the size of the tank you will need to grow to its full potential.

The golden fish of thin body like the Common, Kite Y Shubunkin They are small when they are young, but they can reach around 30 cm. That is why they are normally kept in ponds.

So if you have little space, a goldfish fancy It is probably the best for you. Goldfish fancy They are those that have two tails and a shorter body, and do not become so large, so they do not require so much space.

Once you've chosen your new friend with fins, it's time to take it home and put it in quarantine.


Regardless of where you bought the fish, you should keep them in quarantine. Quarantine is when you put the fish in a separate tank for a while before putting them in the main tank.

Quarantine for your goldfish

Two reasons to keep your new friends in quarantine:

    Quarantine gives the new fish a period of time to "rest" in a separate area before being introduced with your other fish. If you don't have any other fish, you don't have to do it in a separate tank.

The immune system will be very low right now, which makes them prone to disease. Using a quarantine aquarium, we will prevent them from being affected by the fish that are already there, while the new ones are stressed after the transfer. Quarantine allows you to treat all common Goldfish diseases that your fish may have, thus helping to prevent them from getting sick later. If your provider has already quarantined your fish completely, then you don't have to treat all diseases.

This is a sad reality:

Almost all goldfish fish in pet stores are already sick or on the verge of disease.

Pet stores cannot afford to quarantine each shipment of fish for weeks and treat them for the large number of diseases they can carry before they are put up for sale.

They may look good at the time of purchase, but they have gone through a long journey and are very stressed when they reach their final destination. By the time they arrive home, they are almost exhausted and harbor a large number of pathogens invisible to the naked eye.

These pathogens may not cause any problems at first, but as they multiply, the fish end up succumbing.

That is why it is so common to hear: «My goldfish always end up dying».

To recap, if you buy your fish at an animal store, you will need to treat your new fish yourself. And if you already have fish, you will need a separate tank to do this, so that your new fish do not contaminate others.

How to set up your first golden carp aquarium

The way you mount your aquarium will have a huge impact on your success as a goldfish fish breeder.

How to set up your first goldfish aquarium

If you are wondering if you can use the typical ball-shaped fishbowl, the answer is NO.

Goldfish should never be placed in small aquariums or any other unfiltered container. In addition to having a relatively high demand for oxygen, fish waste can be harmful if they are allowed to accumulate.

Y our advice is to take a look at our beginner aquarium guide, with which you will quickly understand why you should not use this type of fish tanks.

The common goldfish They are really one of the largest species and can grow up to 45 cm in length.

A good premise would be to try to choose the largest tank you can afford. He thinks that a larger tank equals healthier fish, and healthier fish equals a happier aquarist.

So how big does the aquarium have to be?

That will depend on the goldfish and how many you want to have in your fishbowl. We have already seen that there are two main types of goldfish, the common and the fancy.

The varieties of Common goldfish fish grow so much that they need 150 liters for the first fish, 75 for each additional.

Yes, although it seems hard to believe, they start so small and end so big.

Now the Golden fancy fish can reach 15 to 20 cm, so 35 to 70 liters per fish is enough. Their size makes them much more suitable for indoor aquariums.

And where do I put the tank?

On the other hand, you will have to choose where to place the aquarium, and it is important to consider all aspects.

First, is there air conditioning or heat sources nearby? Do not place the aquarium in a place where temperatures change sharply.

You should also keep your fish tank away from the windows, since the sunlight that seeps into the aquarium can cause algal growth if there is too much light, in addition to the windows usually have drafts.

If you have no choice but to place your tank where the sun is shining, use a cover that provides shade to reduce the amount of ambient sunlight.

If you have small children and / or pets, especially cats, look for a place that is out of reach.

Substrate, plants and decoration

This part is a bit more personal, because Each aquarist has his own tastes.

Some are happy with a "sunken pirate ship" and some fake plants, and others prefer a aquascaping of natural plants with wood and rocks.

At the bottom of the tank, we have the substrate. Pea-sized gravel is not a good option because goldfish naturally sift the substrate in their natural habitat and can drown with it.

Because we cannot use pea-sized gravel, we have two more options: specialized aquarium sand or large river rocks, both with their own pros and cons, but there is no risk that goldfish will suffocate.

Then we have the aquarium plants. When choosing natural plants, remember that goldfish naturally uproot plants, so you will have to choose resistant and / or fast-growing plants, or your plants will last a sigh.

When you buy your plants, it is recommended to quarantine them in an empty bottle for 1-2 weeks, even if they are sold as free of pests and diseases. If you have no experience with natural plants, we recommend our aquarium plant guide for beginners.

If you don't want live plants, another option is fake plants. False plants are good because they do not require maintenance except to clean the algae occasionally. But nevertheless, fake plants lack one of the best qualities of living plants: they do not clean or purify water.

Once you have your plants, natural or not, you can choose some decorations so that the goldfish have some shelter. The normal plastic ones are fantastic because they provide hiding place for your goldfish and do not change the pH of the water as wood does.

When you are choosing decorations, do not choose any with sharp edges, or that are irregular because your goldfish could get hurt with them. Remember, goldfish will always feel more comfortable and less stressed, which makes them less prone to disease, in a natural-looking environment.

And what else do I need?

But you will need more accessories than a tank to have a happy goldfish ...

    The aquarium water filters They provide a place for beneficial bacteria to grow that keep water quality in good shape for longer.

Beneficial bacteria are those that help keep water healthy. However, you must make water changes even if you have a filter. The filter should be slightly oversized to treat a high production of beef> For water changes, you will need a aquarium siphon. The type of siphon that connects to the sink is> An aquarium heater like the one you can see here to maintain a constant temperature, preventing alterations that can stress the fish. Especially recommended for fancy goldfish. A led aquarium light It will keep your fish and lush plants, while also allowing you to enjoy its contemplation.

Prepare the aquarium water

Water is the medium in which your golden tents will live, and it needs some conditioning so that it is in the right conditions that our friends need.

When it comes to providing water for the freshwater aquarium, tap water must be treated with the appropriate conditioners.

It is important that Never put untreated tap water in your aquarium, as this water brings chemical components that can kill your fish.

Add the appropriate water conditioners

Tap water contains chlorine, chloromins and other heavy metals and contaminants that will burn your fish and kill them. These components must be removed using a water conditioner.

Many recommend Seachem prime because it also reduces the toxicity of ammonia and nitrite for 48 hours, two parameters that are very common in new aquariums.

But even once you add your water conditioner, there is still something else you need to know ... The aquarium is not ready to add your new goldfish.

At this point, many people wait 20 minutes or 24 hours, depending on what the pet store employee has told them, and then add their goldfish.

Who wants to wait, right?

But in a week or so, the fish will be seriously ill, even dead.

This is because the tank has not been cycled first... and also not enough water changes were made to compensate for the lack of an established filter.

Goldfish produce waste that quickly becomes toxic to them. Only two things can be done to eliminate them: water changes or have a good colony of friendly bacteria.

Beneficial bacteria can help convert these wastes into non-toxic forms through a process called the Cycle of nitrogen.

Aquarium cycling

The process called aquarium cycling it is based on the nitrogen cycle and It has to be done before adding any fish to form a colony of beneficial bacteria.

If you already have the fish, it is too late to go through this process.

You will have to make very frequent water changes and add a bacteria culture initiator to accelerate the process, at least every two days for a few weeks until the colony is established in the filter.

If you do not have the fish already, you will have to cycle your aquarium, and in this article we explain how to cycle an aquarium step by step, so you don't miss a single detail.

But keep in mind that an established filter will never do ALL the work for you, will help you reduce it.

Now that you know how to make your aquarium water safe for your new pet, it's time to add the fish.

What is a goldfish?

If you are thinking of getting hold of a goldfish fish As a pet, you have made a great choice. The goldfish or "goldfish" is one of the most common, popular, economical and available types of pet fish today. Both fans and breeders have been fascinated with these brilliant creatures for almost two thousand years, which has result in hundreds and hundreds of different varieties.

Goldfish are an excellent pet for both aquatic enthusiasts and new aquarium owners. But you must know everything you need about these fish so you can take care of them properly, something that we explain below.

Prepare the home of a Goldfish

Common goldfish are actually one of the largest species and They can grow to 45 cm. For a single common goldfish, some experts recommend a tank with a minimum size of 150 liters, a larger one will be recommended for a Goldfish (about 200 liters).

While it is possible to keep a goldfish in a fishbowl, goldfish are very dirty and you will have to change the water much more frequently than in an aquarium. Another drawback of fish tanks is that most of them are too small to adapt to a filtration system, and the rounded and conical design does not provide enough surface for an adequate oxygen exchange.

On the other hand, it is better than do not place the tank in a place where temperatures change Y avoid a lot of natural light since it can cause the growth of algae if it is too bright, in addition to the windows usually have drafts.

As for the aquarium water of our Goldfish, andIt's important that you never put tap water untreated in your aquarium, since Chlorine and other heavy metals and pollutants can kill fish. You must keep the fishbowl full, leaving approximately 5 cm of space at the top.

Goldfish they prefer cold water, but it is also known that they live in slightly warmer waters. The ideal water temperature for common goldfish is between 65 and 68 degrees Fahrenheit. To ensure you reach these temperatures you must have a thermometer in your aquarium.

Acclimatize the goldfish to the aquarium

Now that you have your beautiful new tank ready, let's see how to introduce the goldfish in the tank.

You have to acclimatize the goldfish to the fishbowl

The acclimatization method that we are going to deal with here is the flotation acclimatization method.

    Float the bag in which the fish come in the water for 20 minutes to acclimatize the temperature. Open the top of the bag, without letting water in. Every 5 minutes, add approximately a little water from the aquarium to the bag. Repeat this for 30 minutes. When time has passed, with clean hands or a net, gently collect the fish and pass them to the aquarium. But try not to pour the water from the bag into the tank.

New fish may be a little scared for a while, and it is usually common for them to hide in the bottom until they adapt to their new environment.

If your fish have been shipped recently, you better not feed them for 24 hours. Once you start feeding them, do so in moderation to avoid causing water quality problems.

There is another method of acclimatization that consists of dripping water from the tank, and it is better for fish than the method of acclimatization by flotation. But it requires a way to slowly drip the water from the tank into the new water. We will leave it for another item.

What can a Goldfish eat?

In nature, Goldfish chew aquatic plants, fish eggs, insect larvae, crustaceans and even other fish More smalls. As pets, goldfish remain omnivorous, but the menu changes slightly.

All fish food is not created equally, and foods that are manufactured specifically for Golsfish they will have different nutrients that will be suitable for their development, so that Try to buy specific food for this kind of fish. Goldfish food usually It contains less protein and more carbohydrates than other types of fish food, so we insist that it should be specific food for them and it is strictly forbidden to give human food.

Of course, as a special gift, you can feed your Goldfish with boiled vegetables (cut into pieces of course) like Peas, carrots, oranges or zucchini, lyophilized brine shrimp and blood worms. Further, Try feeding your Goldfish with freeze-dried food instead of live food whenever possible to prevent disease transfer.

How often do I need to feed my Goldfish?

Goldfish are excellent pets for travelers because They can be up to 2 weeks without food. However, it is better to provide your fish with an automatic fish feeder if you plan to leave for an extended period of time.

It is also important not to overfeed your fish. Usually a small pinch of food two or three times a day will be enough, but it depends on the amount of fish. Any food that is left without eating will sink into the bottom of the tank, decompose and contaminate the water. Goldfish metabolisms slow down and accelerate with water temperature, so If the water is cold, you may not even need to eat as often.

How to properly feed the goldfish

Feeding your goldfish well is a very important aspect of fish care.

First, obviously goldfish need food at regular intervals to survive.

In nature, the golden carpines They are omnivorous, they feed on aquatic plants, fish eggs, insect larvae, crustaceans and even other smaller fish.

As pets, goldfish remain omnivorous, but the menu changes slightly.

But the most important thing is that the amount of food they consume directly affects the quality of the water and therefore the fish themselves.

A healthy diet equals healthy fish.

Overfeeding is a serious problem that ends up causing the death of many goldfish. And this is not easy because fish love to eat.

What can goldfish eat?

All fish feed is not the same, and the food that is manufactured specifically for tropical fish, for example, will have different components than the specific food for goldfish.

Goldfish food contains less protein and more carbohydrates than other fish foods. For this, you should not feed a Golden carp A food for betas.

The Colorful fish they will consume these foods for betas, but they will not have the nutrients they need. In addition, it is not recommended to feed a goldfish fish with human food, such as bread, cookies, crumbs, rice or potatoes.

It is advisable to use fish food formulated specifically for goldfish. However, some foods for goldfish are better than others.

Flakes or flakes

For example, commercial flakes, as soon as they reach the water, the scales begin to leach their ingredients, which can lead to water quality problems.

The fish also end up eating a lot of air when eating them. Goldfish feed naturally in the bottom, and can swallow air when they feed on the surface, causing them to lose their balance and float backwards.

To avoid this, soak food in flakes briefly before feeding and avoid using floating granules.

Pellets provide all the nutrients that goldfish need. The best ones have a lot of protein, fat and very little fiber. The type of sinking pellets are ideal.

Make sure your goldfish is large enough to swallow the pellets.

And keep in mind that the flakes begin to lose nutritional value as soon as you open the container, while the pellets maintain their nutritional value much better.

Water changes to have a healthy fish

This is because the biological filter converts toxins in water into a somewhat less harmful substance (nitrates), but you can't totally get rid of that toxic substance.

That substance will accumulate until it begins to harm your goldfish.

The solution? Regularly replace a percentage of tank water with clean new water.

The two most common mistakes that people make when making water changes are: not using dechlorinated water at the correct temperature and removing the golden fish from the aquarium to make a 100% water change.

To make the water changes, get a aquarium siphon to draw water from the aquarium. Now, exactly how much and how often it depends on several factors: the population density of your aquarium, the amount of food you provide to your fish and the results of the water tests.

Approximately we can estimate 30-40% of the aquarium water, while keeping the goldfish in the aquarium, because they will be stressed much less than if we take them out.

You have to make water changes every one or two weeks, even if you keep in mind that if nitrate levels are above 30, you may not be changing enough water often enough.

Watch the behavior of your fish

Watching the fish is important to make sure there are no problems with them. Pay attention to how they are swimming, where they are spending their time in the tank and how they look.

Watch the behavior of your goldfish

Fortunately, seeing the Goldfish is fun and enjoyable, that's why we have them at home, after all.

When you notice a change in their appearance or behavior, make a water change.

It should not be a day when they are not controlled, because sometimes many things can change in a short period of time.

Aquarium cleaning

There are lots of tools for aquarium maintenance that can be used to clean the glass. Some work with magnets and others with telescopic handles.

The key is never to use soap or detergents to clean the fish tank and its decoration. When cleaning your aquarium, always remove any decoration and rinse well with warm tap water.

Try to do not remove the fish from the fish tank while cleaning if possible, since environmental changes can stress the fish and make them sick.

Clean the v /> as is and use a gravel vacuum or siphoner to clean the gravel or substrate.

When using a gravel vacuum, stop once the water level in the tank has dropped by about a third. I should give you enough time to clean most of the gravel and tank. You can finish the rest of the gravel in the next cleaning.

When you change the water, make sure the temperature is the same as that of the aquarium before filling it.

Water Analysis to check the critical parameters

Performing water analysis tests on a regular basis is one of the most important parts of caring for your goldfish, making sure that their environment remains safe for them.

Poor water quality is the main killer of aquarium fish, but the problem is that water can look great. It doesn't have to look cloudy or unpleasant to be extremely toxic to your fish.

Further, Sudden changes in temperature or water chemistry can be harmful, even fatal to goldfish.

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    After adding the fish, the water quality changes over time. By analyzing the water periodically, we ensure that nothing escapes control before it is too late.

    It is recommended to analyze the water every week in an established aquarium, that is, one that has more than one month and has been cycled.

    The most important levels to verify are the levels of ammonia, nitrite, nitrate, pH, Kh Y GH to make sure they are within the recommended ranges.

    The pH is not critical, but ideally it should be between 7.0 and 8.4.

    It is a good idea to check the pH every day. This is because the pH may drop suddenly without warning, leaving your aquarium destroyed.

    It is advisable to use a pH and / or ammonia alert like this in the aquarium to keep it under control without having to analyze the water daily. All you have to do is look at it when feeding the fish.

    Aquarium Requirements

    The first thing you should know is that the tank must be large, approximately must have a capacity of 35 liters for each fish. Keeping them in confined spaces will not reach sexual maturity. These fish can live in small spaces but they will not live comfortably and will not reach sexual maturity.

    The aquarium tank must have enough light, these animals are daytime so they need a cycle of light to stay active during the day and a cycle of darkness to rest at night. In case of not fulfilling these requirements the fish will lose its natural color.

    The water temperature must be between 16 and 24 ° C. To measure the temperature in the market there are varieties of thermometers. The water must be changed every week, you can change an equivalent of 20% of the water in the fish tank or 100% of the water, everything will depend on the decoration that has the same.


    You can buy fish food at pet stores. These fish are very comelones, so be careful not to overfeed them. Place goldfish fish once a day and they will devour them in a minute. The rest of the food that is floating is recommended to remove it.

    Goldfish fish They are omnivorous, that is, they eat vegetables, cereals and dogs. One of the foods that can be given are peas, lettuce, broccoli, earthworms, mosquito larvae, among others. It's all about getting used to eating different foods.

    Common disease

    One of the most common diseases in this type of fish is white spot. Este es un parásito que se aloja en las escamas y las aletas. Para identificarlo observa a tu pez, si tiene puntos blancos en su cuerpo es porque padece de esta enfermedad que es curable. Con solo aislar al pez y tratar el tanque por unos días tu pez se curará.

    Una de las manera de matar al parásito es subiendo la temperatura del agua y agregando sal al tanque. Otra manera es colocando fungicida en el agua del tanque donde se encuentre el pez Goldfish.