Will a Betta Fish Kill a Goldfish: Can they Coexist?

Will a Betta Fish Kill a Goldfish

Betta fish and Goldfish are both popular aquarium fish that are known for their vibrant colors and attractive appearance. However, despite their shared popularity, these two types of fish are not always compatible. One question that aquarium enthusiasts frequently ask is whether a Betta fish will kill a goldfish. In this article, we will explore this topic in detail, covering everything from the temperament of these fish to their compatibility and environmental requirements. By the end of this article, you will clearly understand Will a Betta Fish Kill a Goldfish and Can they Coexist?

What are Goldfish?

Goldfish are among the most popular aquarium fish known for their bright, metallic colors and unique body shape. These fish are native to East Asia and can grow up to a foot in length, making them much more significant than Betta fish. Goldfish are omnivorous and require a diet of both plant and animal-based foods. They are typically kept in larger aquariums with plenty of space to swim.

Will a Betta Fish Kill a Goldfish

Betta fish are known for their aggressive temperament, particularly towards other Betta fish and fish with similar body shapes and colors. Male Betta fish are particularly aggressive and often fight with other males, resulting in severe injury or death. Female Betta fish are less aggressive but can still be territorial toward other fish.

Temperament of Goldfish

Goldfish, conversely, are generally peaceful fish that get along well with other fish of similar size and temperament. They are not aggressive towards other fish and will typically only fight if they feel threatened or if there is insufficient space in the aquarium.

Can a Betta Fish and Goldfish Live Together

Can a Betta Fish and Goldfish Live Together

Betta fish and Goldfish are two of the most popular freshwater fish kept as pets. However, they have different temperaments and environmental needs, making them incompatible tank mates. Betta fish are known for their aggressive character and territorial behavior, especially towards fish with long, flowing fins, such as Goldfish. When kept in the same tank, the Betta will likely attack and injure the Goldfish, causing significant harm or even death. This is because bettas have a more active and aggressive swimming style, while Goldfish prefer a slower and more leisurely swimming pace.

Another critical factor to consider is the water temperature. Goldfish prefer cooler water temperatures, while bettas require warmer water to thrive. The difference in temperature requirements can create a challenging environment for both fish when kept in the same tank. Additionally, Goldfish are larger and produce more waste than bettas, requiring larger tanks with more powerful filtration systems. These conditions may not be suitable for bettas, which can become stressed and ill if the water quality is not well maintained.

Environmental Requirements of Betta Fish and Goldfish

Betta fish and Goldfish are popular freshwater fish with unique environmental requirements. Betta fish are tropical fish that require a warm and clean environment. The ideal water temperature for bettas is between 76°F to 82°F (24°C to 28°C). Bettas need a minimum tank size of 5 gallons with a filter to keep the water quality at a safe level. They also prefer a habitat with plants, hiding spots, and other decorations which mimic their natural environment. Bettas are very sensitive to their surroundings, and sudden water temperature or quality changes can cause them to become stressed or sick.

Goldfish, on the other hand, are cold-water fish that prefer a cooler environment. The ideal water temperature for Goldfish is between 68°F to 72°F (20°C to 22°C). Goldfish require a larger tank with a minimum size of 20 gallons for a single fish and a powerful filtration system to remove waste from the water. Goldfish also prefer a habitat with live plants, rocks, and caves, which provide them with hiding spots and a place to explore.

Both betta fish and Goldfish are sensitive to sudden changes in their environment, and their care requires consistency and attention to detail. Maintaining the appropriate temperature and water quality is crucial to keep them healthy and happy. It is also important to note that betta fish and Goldfish have different environmental requirements, which make them incompatible tank mates. Keeping them in the same tank can cause stress and illness for both species and even lead to aggression or harm.

How to Keep Betta Fish and Goldfish Together Safely

How to Keep Betta Fish and Goldfish Together Safely

First, having a large enough tank to accommodate both fish is essential. A 30-gallon or larger tank is recommended to provide enough space for both species to swim and establish their territories.

Second, ensure the water temperature and quality suit bettas and Goldfish. The ideal temperature for Goldfish is between 68°F to 72°F (20°C to 22°C), while bettas prefer a warmer temperature of 76°F to 82°F (24°C to 28°C). You must monitor the water quality; a powerful filtration system is necessary to remove excess waste produced by Goldfish.

Third, ensure the tank is correctly decorated with plenty of hiding spots and territories for both fish. Goldfish like to swim near the bottom of the tank, while bettas prefer the upper levels. Provide plenty of live or artificial plants, rocks, and decorations to create a natural-looking environment that will help both fish feel secure.

Finally, it is vital to monitor the behavior of both fish closely. If you notice any signs of aggression, such as chasing or nipping, separate the fish immediately. Betta fish can be especially aggressive towards other fish, and it is not uncommon for them to attack Goldfish.

Can you give a Betta Fish Goldfish Food?

It is not recommended to give Betta fish goldfish food regularly. Betta fish have a different dietary requirement compared to Goldfish and require a specific balance of protein and other nutrients to maintain their health. Goldfish food is designed to meet the nutritional needs of Goldfish, which require more carbohydrates.

Regularly giving a betta fish goldfish food can cause nutritional imbalances and health problems for the betta fish. However, you can use goldfish food as a temporary solution in an emergency where you don’t have betta food. This should not be a long-term feeding strategy, and getting the proper betta food as soon as possible is essential to ensure your Betta’s long-term health.

I recommended feeding them high-quality betta-specific food formulated with their dietary needs in mind. This will help ensure they receive the proper nutrients and maintain their health and well-being. Additionally, it is important only to feed them as much as they can eat within 2-3 minutes twice a day to avoid overfeeding, which can lead to health issues such as obesity and bloating.

Will Betta Fish Eat Goldfish Flakes?

Betta fish may eat goldfish flakes, but it is not ideal for them. Goldfish flakes are specifically formulated for the nutritional needs of Goldfish, and they contain a different balance of nutrients compared to the diet of a betta fish. While it may not harm the betta fish to occasionally eat a goldfish flake or two, feeding them exclusively goldfish flakes can lead to nutritional deficiencies and health issues over time.

Are Betta Fish Smarter than Goldfish?

Betta fish and Goldfish have different behavioral and cognitive abilities, and it is difficult to say which species is more intelligent. However, betta fish are known to be more interactive and have a higher level of activity compared to Goldfish. They are known for their curious and playful nature and can recognize their owners and respond to their presence.

On the other hand, Goldfish have a reputation for having a short attention span and a slower response time. However, recent research has suggested that Goldfish can learn and retain information over time and recognize colors and shapes. Additionally, Goldfish have a strong sense of smell and can navigate their surroundings using their sense of smell.


While keeping a betta fish and a goldfish together is possible, it is not always the best idea. Risks include aggression from the betta fish towards the Goldfish and differences in their environmental and dietary requirements. It is crucial to provide a suitable habitat for both fish, with adequate space and hiding places for the betta fish to retreat to if needed. It is also important to feed them a well-balanced diet specific to their needs. 

A betta fish can kill a goldfish, and with proper care and attention, it is also possible for them to live together peacefully. Monitoring their behavior and health regularly and taking necessary steps to prevent any potential problems is vital. The decision to keep Betta fish and Goldfish together should be made carefully, considering their needs and the potential risks.

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