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King Betta Guide: Everything You Need To Know

King Betta Guide: Everything You Need To Know

The domestication of Betta fish started in Thailand more than 150 years ago. At the time, bettas did not have the spectacular colors they have today. However, they were just as aggressive and territorial, especially King betta, hence the name “Siamese fighting fish.”

This guide covers their size, personality, and general care. The King betta grows to 2”-2 ½” (6 cm) and needs a minimum 5-gallon (18.9-L) aquarium. The water pH and temperature should be 6.8-7.0 and 72°F – 86°F (22°C – 30°C), respectively. 

In this article, I’ll discuss King betta extensively, including its physical traits, the best way to feed them, and how to make them less aggressive.  

Siamese Fighting At A Glance

The Siamese fighting fish is not your regular pet fish, as they’re highly aggressive, especially the King betta males. They can barely stand sharing the same space with other male and female bettas and some fish species. The fights can be so intense, resulting in serious injuries.

Size2 – 2 ½ inches (5 cm – 6 cm)
Care LevelModerate
Lifespan3 – 4 years
Minimum tank size5-10 gallons (18.9 – 37.9 liters)
Water temperature72°F – 86°F (22°C – 30°C)
Water pH6.8 – 7.0

Why are King Bettas Also Called The Fighting Fish

The name siamese fighting fish originated in Thailand more than a century ago. Children used to get the fish from rice paddies, put two in a water container, and watch them fight. Soon, people started placing bets to see which fish would emerge victorious.

At the time, this was a source of entertainment. However, King bettas are naturally territorial, and this fight for space earned them the title Siamese fighting fish. In hindsight, it’s not surprising that two very territorial fish fought when put together in a small space. 

This personality trait has remained the core feature of King betta fish. 


The King betta is a stunning fish, which is largely attributed to its striking colors, beautiful fins, and tails.

These fish come in a range of bright and vibrant colors, including red, blue, green, and orange. The males typically exhibit more vivid colors than the female, though both genders are visually appealing.

Unlike other betta species, the King betta has a larger body size but shorter fins, creating a unique profile that sets it apart from other fish. Despite its smaller size, the King betta remains a popular choice among aquatic enthusiasts, with males typically growing to a length of 2-2 ½ inches and females slightly smaller.

Temperament & Behaviour

King betta males are known for their highly aggressive behavior, which means they are likely to attack any other male bettas that they perceive as a threat.

For this reason, it’s recommended to keep your king betta separate from other fish and house them in their own aquarium. If you do choose to keep them with other fish, it’s important to carefully select tank mates with a calm and non-threatening demeanor.

If you notice your king betta swimming very quickly and appearing frenzied, it may be an indication that it’s feeling stressed. Get to know their behavior so you can take appropriate measures to ensure a safe and peaceful environment for them.

Aquarium Setup

The natural habitat for betta fish includes heavily vegetated small streams, rice paddies, and river basins. These are shallow water sources, and they warm up quickly, which is why bettas tend to swim close to the surface. 

Fortunately, the King betta has a specialized labyrinth organ that allows them to take in oxygen from the air, and it supplements the dissolved oxygen in the water. The other function of the labyrinth organ is to allow the fish to breathe when it comes across dense vegetation in its natural habitat.

You should do the following when setting up an aquarium for a King betta.

  • Minimum tank size: 5 gallons (18.9 L). Adjust the size upwards for a community aquarium.
  • Water pH: 6.8 – 7.0
  • Water Temperature: 72°F – 86°F (22°C – 30°C)
  • Water hardness level: 5 – 20 dGH.
  • Vegetation: Java Fern, Anubias, Marimo moss ball, Cryptocoryne, Water sprite, Amazon Sword plant, Vallisneria, and Betta bulb
  • Filter: Low-flow filtration sponge filters.

Most fish species are sensitive to the water conditions in the fish tank, and King betta is no different. Fluctuations in water temperature and pH levels make King bettas susceptible to diseases.

API Fresh Water Master Test Kit (available on has 7 bottles of testing solutions that cover over 800 tests. They will monitor the aquarium’s water pH, ammonia, nitrate, and nitrite levels, are easy to use, and give accurate results. 

Keeping King Betta in Solitude Aquarium

King betta fish, like other bettas, don’t live easily with other fish species in a community aquarium. This species is happy to stay alone as long as they have sufficient space to explore the aquarium. King betta hardly ever gets lonely, but they do get bored easily. 

Signs of boredom in King bettas include the following:

  • Loss of appetite
  • Lack of energy
  • They regularly hide instead of exploring

These signs may also indicate poor health. By making the aquarium more entertaining, you can confirm if your King betta is ill or bored. For example, an obstacle course, betta fish toys, or an exercise mirror will make the aquarium more stimulating for King betta fish. 

This Zoo Med Floating Exercise Mirror (available on has a mirror attached to a floating ball that helps bettas exercise and reduces boredom. It also reduces their aggressiveness. 

When the tank has sufficient vegetation, play items, and space, a King betta will live comfortably in solitary. However, you can create a suitable environment for the king in a community aquarium. 

Keeping King Betta in a Community Aquarium

Sometimes, a King betta can peacefully live in a community aquarium. It takes more work and planning to ensure all the living organisms in the tank live cordially, so if you decide to put a King betta in a community aquarium, you must remember the following:

  • Don’t put a King betta male with another male or female unless you are breeding them. You’ll start a war that may end with injuries that may be fatal.
  • Avoid bright-colored fish species because they are easy to spot. A King betta may confuse them for a male betta, triggering an attack.
  • Opt for bottom-dwelling fish, like Khuli loaches, because they stay away from the King betta’s path. 
  • Don’t overcrowd the tank because this will deny the King betta the space it needs to explore. The King betta will also be more aggressive in fighting for dominance in the tank. 
  • Add a gallon (3.8 liters) of water above the minimum quantity required for the King betta for every extra fish you have in the community aquarium. 
  • Move the King betta to the community tank and not the reverse. If you add other fish species to the aquarium, the King betta will have reason to fight the invasion. 
  • Recreate King Betta’s natural habitat as much as possible. This means the water needs to be as still as possible. A strong current will be distressing, and the fish will display its aggressive side more often. 
  • Use a filter that has an adjustable flow for easier management.
  • Female King bettas are less aggressive and more accommodative of other fish species and female bettas in a community tank. However, you should have more than four female King bettas in the same tank because they’ll develop dominant behavior, resulting in fights.  

Tank Mates

In their natural environment, bettas are not community fish. If you do decide to pair your King betta with other fish, look for tank mates that have a placid and non-threatening bottom-dwelling species, such as Khuli loaches or Corydoras catfish.

Avoid bright-colored fish as mentioned earlier as this will almost certainly trigger an attack.

King Betta Care

Once you set up the ideal environment in the aquarium, your King betta fish will be comfortable. Maintaining the right care routine for King bettas is important, including the right diet, water quality, and tank mates if you choose to have a community aquarium. 

You can take care of King betta fish by feeding it once or twice a day with a high-protein diet of fish pellets and flakes. You must also monitor water temperature, pH, ammonia, and nitrate levels daily. Check the filter regularly to confirm it’s working well, and change the water as needed.

The care of King bettas is similar to that of other fish in the aquarium. However, you need to exercise caution with the amount of food you feed it and the bite sizes. Your King betta’s behavior will also tell you when something is wrong with the tank. 

This video gives tips on how to care for King bettas:

Food & Diet

King bettas natural diet consists of insects and their larvae, so you’ll want to provide them with a well-rounded, high-protein, diet that caters to their carnivorous nature.

To ensure that bettas receive adequate nutrition, I recommend including in their diet specialized pellets, frozen foods, and flakes that are specifically designed for their dietary needs.

Additionally, you can supplement their diet with live foods such as mosquito larvae, bloodworms, and daphnia. Make sure you source live foods through a trusted and reputable supplier to avoid introducing parasites into the aquarium.

King bettas are quite greedy. Their stomachs are only the size their eyeball, but if you give them too much food or feed them too often, they will keep eating. When bettas overeat, they can develop several problems.

Symptoms of Overfeeding

  • Constipation or bloating. If your King betta’s stomach starts changing color to white or gets too big, it is likely a result of overfeeding. 
  • Increased vulnerability to diseases
  • The fish will get overweight.
  • Unused food will elevate ammonia levels in the aquarium. 

Please be extremely careful when feeding your King betta. The ideal schedule for feeding them is once a day, but if you feed them twice, reduce the quantity by half and give a 6-hour break between feeds. 

When using fish pellets, give the betta two to four fish pellets a day. These pellets absorb water and are quite filling. Occasionally substitute the pellets with frozen shrimp and flakes.

Ensure you give the King betta food that can be consume in 2 minutes. If you give it more food, the rest will collect at the bottom of the tank. Keep monitoring the tank, and if the food pile increases, check if your betta is sick or reduce the amount of food you give to your betta. 

Whatever the problem, you must immediately remove excess food from the tank. The food will contaminate the water and even encourage the Siamese fighting fish to overeat when it comes across the food.

You can use Penn-Plax Aquarium Fish Net (available on to remove excess food in the aquarium. It’s sturdy and has a braided handle to improve durability, and it’s multi-functional because it can remove sediments in the fish tank and move the fish when cleaning the aquarium.  

Why Your King Betta Is Not Eating

When it comes to feeding the King betta, you’ll have two main concerns, overfeeding and underfeeding. However, sometimes the Siamese fighting fish may not eat the food, and you need to find out why it has lost its appetite. 

The King betta will stop eating for various reasons:

  • Stress resulting from changes in water temperature and pH levels.
  • Activities like tank cleaning may affect the betta’s appetite. 
  • An aging King betta will also become less active and eat less or no food. 
  • The fish may be discontent about being limited, especially in community aquariums. 
  • Poor health
  • Your fish may not like the food.

You’ll need to go through the possible causes to find out why your King betta is not eating so that you find the best solution. 

King betta can go for 14 days without food, so when it misses a meal or two, there’s no cause for concern. However, if the betta goes for days without food, it’s a sign something is wrong, and you need to find a solution quickly. Otherwise, you risk losing your King betta. 

King Betta Diseases, Prevention, and Cures

King bettas, like other bettas, are a hardy species. However, they are sometimes vulnerable to bacteria, fungi, and parasites. Watch your King betta frequently so that you can identify any abnormal behaviors and physical signs of sickness.

Some of the signs to look out for include the following:

  • Lose of color intensity, specifically in male King bettas
  • Loss of appetite
  • It loses some of its aggressiveness, even when provoked.
  • Labored breathing. The King betta will start breathing rapidly or appear to gasp for air. The fish is also more likely to spend more time closer to the aquarium’s surface.
  • The betta fish will also be sluggish when it is usually active. 
  • Damaged or clamped fins

Ich/Ick/White Spot Disease

Ich is caused by parasites and is characterized by small white spots. You can easily see these marks on your King betta through the aquarium, as they are common on the body and fins of the King betta. The fish will also constantly rub against objects in the tank to reduce irritation.

Stressed King bettas and those living in poor water conditions are most vulnerable to ich. A contagious tank mate can also introduce the parasite to the community aquarium. 

Treatment options include the following:

  • Isolating King betta from other tank mates.
  • Destroy the parasites in the water by slowly increasing the water temperature to 81°F – 86°F (27°C – 30°C).
  • Add an airstone to improve oxygen circulation when water temperature increases. 
  • Daily water cycling (25% – 50%).
  • Treat the ich parasites. 

API Liquid Ick Cure (available on is a commercial treatment for ick and bacterial infections in ick. It kills the parasites within 24 hours, but you should use it every day for five days to ensure no parasite lingers in the aquarium. 

Fin and Tail Rot

The other most common disease in King bettas is fin and tail rot, which is a bacterial or fungal infection that usually attacks King bettas with poor immunity. Bettas in small bowls or uncycled tanks also fall victim to this disease.

The fins usually start to rot, but unfortunately, they can be mistaken for torn fins resulting from injuries during fights. 

Signs of fin and tail rot include the following:

  • Brownish, whitish, or spots on the fins and tail’s edges.
  • Black or bloody fin edges. 
  • Fuzzy growths on the fins.
  • Loss of fin membranes. 
  • Difficulty swimming. 

Check the top (dorsal), tail (caudal), and anal (bottom) fins for signs of fin and tail rot.

Causes of Fin and Tail Rot

  • Overcrowding
  • Low water temperature (below 72°F (22°C)
  • High ammonia, nitrite, and nitrate concentration
  • Uneaten fish food due to overfeeding 

Treatment of Fin and Tail Rot

  • Maintain water pH at 6.8 – 7.5
  • Maintain water temperature between 72°F – 86°F (22°C – 30°C)
  • Change 50% of the water with unchlorinated water
  • Clean the substrate and remove excess fish food and other debris
  • Replace old, chipping decorative media, and wash those that are still useful. Avoid using soap
  • Monitor the fish over the new few weeks to see if the rot is drying or getting worse
  • Clean the tank if the rot is severe
  • Administer an antibiotic

King Betta FAQs

What is the difference between a King betta and a regular betta?

The King betta tends to be larger in size and has shorter fins compared to the regular betta. When King betta perceives a threat, they will flare their fins to look more imposing.

How big of a tank does a King betta need?

King bettas need a minimum tank size of 5 gallons (18.9 L) that will need to be adjusted upwards for a community tank. Add a gallon (3.8 liters) of water above the minimum quantity required for the King betta for every extra fish you have in the community tank. 

How many pellets should a King betta eat?

Feed your King betta two to four fish pellets a day. Pellets can look like insects when they sit on the surface of the water.

How often should I feed my King betta?

Feed your King betta once or twice a day. If you are feeding them pellets, keep in mind they expand in water and are very filling for your Betta fish.

What is the most aggressive betta?

Plakats are the most aggressive betta fish and they have a habit of jumping out of their tanks.

Wrapping Up

King bettas are fairly easy to keep, and their maintenance is manageable. Their territorial nature and active nature demand that they have sufficient space to move and play. The care of King bettas is similar to that of other fish species. However, because of their dense fins, you need to be concerned about the effect of poor water quality on their immunity and general health.

I’m Elle, the founder of FishHQ. I created this website to share knowledge, tips, and inspiration for beginner hobbyists to help them create a healthy, happy, and vibrant environment for their fish to thrive. Read more...