One of the most popular aquarium fish is probably the goldfish. For more than 1000 years, the goldfish has been kept and bred by humans. Almost everyone knows them and associates them with a typical aquarium. But how is the fish kept in an aquarium and what to look out for?
These and many other questions, such as the aquarium, breeding, or typical diseases, we would like to answer you in the following article. Also, we will finally answer the question of whether the goldfish is the right fish for you.
Easy / Hard (depending on the species)
25 - 30 Years
up to 15 inches
Minimum Tank Size
60 °F - 75 °F
6 – 8
Possible Tank Mates
In the aquarium only other species of goldfish recommended
Many people associate the goldfish with a small aquarium, but this is actually forbidden according to the animal protection law. Goldfish need much more space than you might think. The up to 15 inches tall fish need at least a 20 gallons tank. With each additional fish, the space requirement increases by 10 gallons. However, if you follow a few simple principles, the goldfish is very easy to care for fish, which is also suitable for beginners.
The origin of the breeding comes from China, where different species were kept over 1000 years ago. Now there are well over 100 different breeding forms, which all have their own special characteristics. They differ on the one hand in color but also in the required water temperature. The size of the breeding forms can also vary slightly.
If you want to keep a fish school, a pond is recommended, because here the animals have much more space to live out. Due to its size, the goldfish is less compatible with other fish. In an aquarium, it should be kept with other goldfish species. Fish of other species should not be in a tank with the goldfish.
Appearance of Goldfish
The appearance of a goldfish is highly dependent on the particular breeding. Depending on keeping in an aquarium or a pond, different forms are better or worse suited. The largest breedings can grow up to 15 inches. Breeds for a tank have a size up to 10 inches. The body shape and especially the fins also differ depending on the breeding. The color is always between yellow and orange.
Goldfish can reach a very old age compared to other fish. Depending on the attitude and species, they can live up to 40 years. In a pond, the fish usually live longer than in an aquarium — the smaller the tank, the lower the goldfish’s life expectancy.
In a small glass, the fish usually do not survive longer than 2 years. A species-appropriate husbandry is therefore significant. The average life expectancy for a goldfish in an aquarium is around 20 to 25 years, and in a pond 30 to 40 years.
In character, goldfish are very social and sociable fish. For this reason, the animals should never be kept alone. As a minimum, a group of 3 animals. They are rather calm fish, which do not swim very fast and a lot, but still need a lot of space. They are mainly found in the middle layers of water and burrow in the bottom when looking for food.
How many Goldfish should you get?
When setting up an aquarium, one should always take into account the needs of the animals. Goldfish are sociable fish, which do not like to be alone. Therefore, you should always keep at least 3 goldfish together in one tank. However, it is important to consider the space requirements. Because, as mentioned, 10 gallons is needed per goldfish. Whether you keep male or female goldfish together is basically irrelevant. A balanced number of fish is always recommended.
The aquarium is instrumental in how well and long the fish live. A tank that is too small significantly reduces the life expectancy of goldfish. A minimum 50-inch tank with at least 20 gallons should be used for species-appropriate husbandry. For each additional fish, space requirements increase by about 10 gallons. Generally, this information varies by breeding form. Large breedings over 10 inches are more suitable for ponds than for aquariums.
The bottom of the aquarium should be covered with gravel. Goldfish like to forage on the bottom, which would otherwise stir up the bottom considerably. To still keep the water clean, a large filter is essential. A heater is optional in a goldfish-only tank. On the other hand, lighting should be installed in any case and should be active between 8 to 10 hours.
For the plants, you should pay attention to stable and robust species. Goldfish like to eat the leaves of the plants, which may cause smaller ones to suffer. They also dig up the soil and thus the roots. Nevertheless, plants are very important because they increase the quality of life of the fish by providing hiding places and retreats and increasing the water quality.
Water Parameters for Goldfish
Since goldfish are also pond tanks, they are very tolerant of water values. Temperature fluctuations between 40 °F to 80 °F are no problem for the fish. The fish then lower their metabolism and hardly move. The aquarium can be operated either with or without a heater. Just some breeding forms, especially for an aquarium, are not suitable for very low temperatures.
The optimal pH of the water is between 7 and 8 but can also depend somewhat on it. As with the temperature, goldfish are not very demanding in terms of water quality. However, the optimum temperature is in the range of 60 °F and 75 °F.
More exact values of the other water factors are clearly presented in the following table.
60 °F - 75 °F
< 25 ppm
7.0 - 8.0
< 20 dGH (<356 ppm)
10 - 14 dKH (178 - 249 ppm)
Varieties of Goldfish
Goldfish come in countless breeding forms. Each of them has special optical characteristics. They differ in size, shape, and color. But also, the respective water parameters can differ depending on the breeding. Probably the biggest difference can be seen in the fins of the fish. Breedings usually have significantly larger fins than the classic (feeder) goldfish. Frequently occurring breeds, which are visually more spectacular, are, for example:
- Fantail Goldfish,
- Veiltail Goldfish,
- Lionhead Goldfish,
- Comet Goldfish,
- Black Moor,
- Ryuikin Goldfish.
Goldfish Diet and Feeding
The right diet is crucial for the fish’s health, just as it is for us humans. Since the animals themselves do not influence it, their quality of life and health is your responsibility. How to feed the animals correctly is explained in the following section.
In nature, goldfish are typical omnivores. They eat whatever they can find. This includes insects and their larvae, worms, and small crustaceans. They also pluck at aquatic plants and algae and burrow on the bottom of the water.
What should I feed Goldfish?
You have many options when feeding goldfish. The animals are omnivores and can be fed different foods. For example, dry food is suitable, as well as frozen, live, or green food. The quality of the food is important for the health of the fish. Therefore, high-quality live or frozen food should be fed regularly. The best food is mosquito larvae or water fleas and green food, such as lettuce or cucumber.
How often should I feed Goldfish?
Goldfish should be fed once a day. For the amount of food, a guideline is that all the food should be eaten within 2 to 3 minutes. If food remains in the tank, it is too much.
If you don’t want to feed your fish yourself every day, you can also use an automatic feeder. This will automatically feed the preset amount into the tank at the same time. You can find a detailed test of different models here.
How long can Goldfish go without food?
Goldfish can go without food for a long time. Therefore, one day without food is not a problem. But even after several weeks, adult fish can get along without food. In a pond, for example, this is the case in winter. In this case, the fish reduce their metabolism very much and hardly move. Thus, they are also able to survive in cold waters.
Read more about it here: How long can Fish go without Food?
Goldfish Tank Mates
If you want to keep other species in a tank beside the goldfish, you should consider some aspects. The requirements of a goldfish are not difficult to implement but quite specific. So the animals need a lot of space, where there is little space for other animals. So if you want to put more animals in a tank, it should hold at least 80 gallons.
Also, you should pay attention to the fish’s size so that the species have enough space. Another aspect is the water temperature, which is relatively low for goldfish. The possible aquarium partners must be compatible with this temperature. Generally, it is recommended to keep goldfish alone because of their requirements. A common variant is to combine different breeding forms. We would always recommend this.
If you still want to combine other fish in a tank with the goldfish, we recommend:
- Cardinal Fish,
- Bristlenose Plecos,
- Rosy Barbs,
- Other goldfish species,
- Cory Catfish.
If you want to breed goldfish, it depends less on you than on the animals. For the fish to spawn, they only need suitable tank conditions. When spring comes or the temperature rises, the females begin to lay eggs in the corner of the tank. The male fish then fertilize them.
These eggs must then be removed from the tank and put into a small tank. It is important to use a fine sponge filter that does not suck in the eggs. The temperature in the tank can be the same as the main tank. After 4 to 7 days, the young fish hatch. After a few more days, they start to swim and need food. When they have reached a certain size, they can go back into the tank to their parents.
Common Goldfish Diseases
Important for goldfish’s health is, above all, a sufficiently large tank and a balanced diet. Otherwise, the stress level of the fish increases sharply, which affects their health. If the fish seem stressed and behave differently, the first thing to do is check the water conditions. Wrong temperature or changed water parameters can also lead to stress and diseases.
Especially the ammonia value is significant. If it is not in the right range, half of the water should be changed immediately. If you recognize a fish as sick, you should immediately remove it from the tank and isolate it. Besides, a water change is the first step to prevent transmission to other fish. We have listed typical diseases in a goldfish tank in the following table.
Injuries to the fins of the Fish.
Transmitted by parasites, which can enter the aquarium through new fish.
A diseased fish should be separated immediately and the tank cleaned so that the disease does not spread further.
White spots on the body and the fish rubs against hard objects.
Is transmitted by bacteria, which often come into the tank through new fish.
A fish should therefore be immediately separated and the tank cleaned. Also an Ich drug should be applied.
Symptoms include a white irritation of the skin and cloudy eyes.
The bacteria are in almost every tank, but only attack weak and stressed fish.
When the disease breaks out, the water should be changed frequently and the stress of the fish should be reduced. Also an bacterial drug should be applied.
Swim Bladder Disease
The fish swims sideways and upside down.
The disease can be genetically predisposed.
The fish can not be cured. Sometimes it disappears again on its own.
Conclusion – Is the Goldfish the right fish for your tank?
The goldfish is probably one of the most typical aquarium and pond fish in the world. Nevertheless, a small goldfish bowl, as it is in most heads, is prohibited. A large tank of at least 20 gallons is needed to keep goldfish in a species-appropriate manner. Each additional goldfish requires an additional 15 gallons. For the animals to live healthy and long, you should never underestimate this. If you have a large enough tank or even a pond, the fish require minimal experience and little knowledge.