What You Need to Know About King Bettas

In the world of betta fish, some reign supreme. King bettas, or Betta imbellis, have been domesticated for over 400 years.

These fish come from Laos, Myanmar, and Thailand, where betta fighting originated using wild betta fish. A king betta is a fighting betta fish line bred specifically for aggression.

King bettas are also bred as ornamental fish and beautiful in their own right.

king betta atf


Although sometimes confused with giant bettas, king bettas are the same size as regular betta fish. Giant betta fish, on the other hand, is from 5-7″ inches long!

King bettas have more of a Plakat look, which is how they often get confused with Giant bettas.

Ornamental king bettas have been hybridized with other species (B splendens, B smaragdina, and B mahachaiensis) to create different colors and characteristics.

king betta appearance

Unique Differences 

King bettas are agile and fast, more so than Betta splendens. They have shorter fins and a broader tail to improve their fighting skills.


King bettas have a life span of two to three years. Betta splendens live up to five years.

Average Size

The average size of a king betta fish is similar to other betta species, 2-3″ inches. If you were to make a betta size comparison, you would see little difference.

King Betta Care Requirements

Tank size

A general rule of thumb for housing fish is 1″ inch of fish per gallon of water. Bettas need a minimum of 5 gallons to support the nitrogen cycle in the tank.

The larger the tank, the more stable the nitrogen cycle is. Organic materials such as live plants, leaf litter, and driftwood also encourage the growth of good bacteria, which helps stabilize your tank’s chemistry.

The water in a fishbowl gets polluted too fast and needs changing too often. This could give your fish shock and lower their resistance to diseases such as fin rot and ich.

A bigger fish tank, such as ten gallons, would be better for your King betta and give you more room for healthy live plants and fun decorations. 

Water Parameters

Ideal Water Parameters for a Betta Fish Tank Include the following:

  • Temperature: 78-80° degrees Fahrenheit (25.5-27° C)
  • pH: 6.5-7.5
  • Ammonia and Nitrite: 0 ppm
  • Nitrate: < 40 ppm
  • gH: 3-4 dGH (50-66.7 ppm)
  • kH: 3-5 dKH (53.6-89.4 ppm)
  • Minimum Tank Size: 5 Gallons

Use chemical testing to check the pH, ammonia, nitrate, and nitrite levels often. Keep a clean tank and change the fish tank water weekly.

Maintaining good water parameters will help keep your betta healthy. Poor water conditions are the number one cause of disease.

Tank Filter

As bettas come from an environment with slower-moving water, make sure the gallons per hour do not exceed four times the size of your tank. Bettas do not like a strong current.

The filter must move the water in the tank through it 4-6 times per hour. A filter with adjustable flow settings is a good idea.

Some fishkeepers suggest using an air-powered sponge filter set for gentle turnover to more closely mimic the stillness of the betta’s natural habitat.

Aquarium Heater

A tank heater with 3-5 watts per gallon of aquarium water is preferable. Bettas come from a tropical environment and so need warmer water.

A submersible heater with a thermostat will give you the best experience. Using two heaters for larger tanks is a good idea.

Use a separate thermometer to monitor the temperature in your tank. Water heater thermostats are sometimes unreliable.

Artificial Lights

Do not have excessively bright lights in your betta’s aquarium. They prefer a more natural, dark environment and hide in a shady spot if the light is too bright.

Bettas prefer 1 watt or less per gallon. You will have to balance your betta’s preferences with the needs of the plants in your aquarium.

Plants and Decorations

king betta decorations

Including live plants is a terrific way to improve water quality and enrich your betta’s environment. King bettas will appreciate places to hide and rest.

Silk plants are also acceptable substitutes for live plants. Artificial plastic plants are not a good idea.

They may have sharp edges, which might injure your betta’s fins. A cut on a betta’s fin will lead to fin rot if not cared for.

Decorations must not have sharp edges, either, and must be rust-free without flaking paint.

Betta-safe caves, floating logs, or large rocks make nice decorations for a betta tank and provide plenty of hiding and resting places.

Driftwood provides a slow release of tannins and a place to attach plants. King bettas do well with a lot of plants to provide surface cover as well.

Bettas feed at the water’s surface and breathe at the top of the tank using their labyrinth organ, so ensure you have enough space. Trim surface plants as needed.

For a natural look, provide a layer of leaf litter on top of the substrate. This also encourages the growth of beneficial microbes as the leaves decay.


Smooth, natural gravel is the best substrate for your betta fish tank. Gravel holds plants better.

Natural rocks will help the colors of your betta stand out. Neon rocks will distract from the beauty of your fish and plants.


In nature, wild bettas eat insects and insect larvae.  Bettas are carnivorous, which means they need a high-protein carnivore diet primarily consisting of meat proteins.

Your betta will find live food, such as mosquito larvae stimulating and tasty. Do not get them from your backyard, they may carry parasites.

Always source food from a reputable seller. It is worth the extra expense to ensure your fish stays parasite-free.

King bettas enjoy a varied diet with frozen brine shrimp, bloodworms, and other frozen food. Bettas also eat pellets and flake food, which are easy to store.

Only feed your fish twice daily, roughly enough food to last him for a few minutes. Betta fish will easily overeat and become bloated and constipated.

Your betta’s stomach is about the size of its eye, do not feed it more.

Possible Diseases

king betta diseases

King bettas are susceptible to the same diseases as other bettas. Most are preventable with good water conditions and low stress.

If your betta gets sick, separate them into a hospital tank if they are in a community tank to keep tankmates from harassing your sick fish. Treat the whole tank if called for by the medication.

Some common diseases bettas get are:

Fin and Tail Rot

  • it is caused by a bacterial infection, commonly due to injury and stressful conditions
  • the fins look shredded
  • it is treated by water changes and medication


  • it is caused by the velvet parasite, they succumb to stressful conditions
  • there is a gray or whitish coating on the body
  • it is treated by water changes and medication


  • it is caused by the ich parasite, they succumb to stressful conditions
  • it looks like white spots all over the body, gills, and fins
  • it is treated by water changes and medication

Fungal infections

  • it is caused by stress or injury lowering their resistance to the fungus
  • there are fluffy white-looking patches on your betta’s body
  • it is treated with a fungicide and water changes


  • it is caused by overfeeding
  • the symptoms are poor appetite, swollen belly, and no feces on the tank bottom
  • it is treated by fasting your betta for a couple of days or feeding them a defrosted frozen pea (with the skin removed) for fiber to get their digestion moving

Swim bladder disease

  • it is caused by a bacterial infection triggered by poor water quality, injuries, and stress
  • your fish may tip to the side, float to the top of the tank, or swim upside down
  • it is treated with antibiotics and water changes

Maintaining optimal water parameters is key to keeping your betta healthy and safe. Perform regular water changes, and make sure their environment is betta-friendly.

Do not overcrowd your betta, and make sure all tankmates are getting along. This will avoid stress and injuries from fighting.

Behavior & Temperament

king betta behavior

Male king bettas are extremely aggressive fighters and should be housed alone. They should not be kept with females of their own species unless you are breeding them.

Their aggressive temperament makes them superior fighting fish and terrible roommates.

Do not house other varieties of betta with them; they are agile swimmers and will beat them in a fight.

Tank Mates

Bettas are naturally lone fish; they do not school or live in communities. They do not get lonely, although they may get bored.

As aggressive as they are, King bettas do not need tank mates. Do not add a regular Betta splendens to the tank.

They will fight, and the regular betta will be at a disadvantage as they lack the shorter fins and broad tail of the King betta and will be slower.

If you get buddies for your king betta, a peaceful bottom dweller such as a Kuhli loach or Corydoras catfish is a good idea.

Do not put in any fish with flowing fins or bright colors, they will trigger the betta’s aggression.

Other possible tank mates for a king betta are:

  • Female Guppies
  • Ghost Shrimp
  • Malaysian Trumpet Snails
  • Ember tetras

Check out our full list of betta tank mates to find out which are the best (and worst).


King bettas are egg layers and bubble nesters and need places for the males to create their nests. The females will lay their eggs there, protected by the male.

Breeding bettas prefer a more natural environment of blackwater conditions, which you create using tannins from Indian almond leaves or driftwood.

For more on tannins in the betta tank, visit our article on the benefits of tannins.

Watch out for aggression from the male betta towards the female. Fights might cause serious injury or even death.

Your breeding tank should have a tightly fitted cover to keep humidity and warmth in for the fry. They must be able to breathe at the top to develop their labyrinth organ.

Leaf litter on the substrate will provide a breeding ground for microbes which the betta fry will eat after they are done with their yolk sac.

Feed the delicate fry Artemia nauplii and micro-worms after that.


King bettas range in price from $20 – $45 depending on fin types and coloration. Rare fin types and beautiful color combinations are priced accordingly.

Some betta fish are valued at upwards of $1,000!

The most expensive Betta ever sold was a Halfmoon Plakat in the colors of the Thai flag. This red, white, and blue fish sold for about $1,500.

The Halfmoon Plakat tail shapes, and koi colorings are valued the highest. Learn more about the Halfmoon Betta fish here.


King bettas are not as easily available as Betta splendens. Make sure you get a King betta, not a Giant betta which is a completely different species of betta.

It is very common for stores to use the names interchangeably.

Frequently Asked Questions

What makes a betta a king?

A King betta is a different species of betta, Betta imbellis. They are about the same size as regular bettas but have shorter fins and a broader tail, enabling them to maneuver quickly. 

King betta are more Plakat-shaped like the Giant betta and often get mislabeled as such.

Are King Bettas aggressive?

King bettas were specifically bred to be aggressive so yes, they are very aggressive and will defend their territory to the death.

What is the biggest type of betta fish?

The biggest type of betta fish is the giant betta. It was created in 1999 when some Thai betta breeders became aware of a very large specimen in their stock and subsequently bred bigger bettas.

The giant betta fish’s scientific name is Betta anabantoids. They get up to 5-7″ inches long. There are now many different colors of Giant bettas.

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Written by

Contributing Writer

Wesley Oaks has a background in web publishing and decided to combine his skillset with his enjoyment of betta fish. When he isn’t working behind the scenes for Betta Fish Bay, he’s homeschooling his kids and soaking up quality family time.

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