Raja Betta (Betta sp.) in a freshwater aquarium
Intermediate careSemi-aggressiveTop/Mid dwellerSoutheast Asia

Raja Betta

Betta sp.

The Raja Betta (Betta sp.) is a semi-aggressive fish that's a good step up once you have a little experience. Give it a tank of at least 100 litres (26 US gallons), water held at 72-81°F, and a pH of 6-7.5.

Care levelIntermediate
TemperamentSemi-aggressive
Min tank size26 US gal
pH range6-7.5
Temperature72-81°F
Max size2.8 in (7.0 cm)
Captive lifespan3-6 years
SchoolingNo
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Captive lifespan reflects typical experience in a home aquarium, not maximum recorded age; genetics, sourcing, and care vary.

Natural distribution

Southeast Asia

  • East & Southeast Asia

Regional colours match the stocking calculator's origin map.

Raja Betta Tank Setup

A single male is happiest in at least 100 litres (26 US gallons), heated to 72-81°F, with a pH around 6-7.5. Give him a calm water surface to breathe at, and fit a lid - bettas can jump.

What Do Raja Bettas Eat?

They have small mouths, so stick to small foods: crushed flake, fine granules, and now and then a treat of frozen or live foods such as daphnia or baby brine shrimp. Anything too large simply gets ignored.

Raja Betta Tank Mates

Predatory; may eat small fish or inverts. The Raja Betta is semi-aggressive, which is the first thing to weigh up when you choose tank mates. It's predatory, so anything small enough to fit in its mouth will be treated as food rather than a companion. Before you buy, run your full stocking list through our stocking calculator. It weighs temperament, adult size, and water needs together, which a single species page can't do on its own.

Are Raja Bettas Good for Beginners?

Not a sensible first purchase. Get the tank cycled, keep easier fish stable for a year, then revisit if you still want the extra work this species demands.

Raja Betta - frequently asked questions

What size tank do Raja Bettas need?

Raja Bettas need a tank of at least 100 litres (26 US gallons). A bigger tank is always easier to keep stable, and gives them more room to settle in and behave naturally.

What water parameters do Raja Bettas need?

Keep them at 72-81°F with a pH of 6-7.5, steady rather than chased to an exact figure. In a cycled tank, ammonia and nitrite should both read 0 ppm, with nitrate kept low through regular water changes.

What do Raja Bettas eat?

Raja Bettas have small mouths, so they need small foods. Crushed flake and fine granules form the staple, with the occasional treat of frozen or live foods such as daphnia or baby brine shrimp. Feed small amounts once or twice a day, and remove anything they don't eat.

Are Raja Bettas good for beginners?

Raja Bettas are best for keepers with a little experience. They are manageable once you test water regularly and catch problems early; a complete beginner may prefer something more forgiving first.

Common mistakes with Raja Bettas

  • Underestimating tank size - the minimum footprint is 100 litres (26 US gallons); impulse buying into a smaller tank leads to stress and shortened lifespan.

Building a community? Run the full list through the stocking calculator before you add anything else.

Fish to avoid mixing with Raja Bettas

These well-known species are commonly sold alongside this fish but are not recommended tank mates - verify before purchasing.

  • OscarPredator - Oscar will eat or injure smaller tank mates
  • Pea PufferPredator - Pea Puffer will eat or injure smaller tank mates
  • Plakat BettaPredator - Plakat Betta will eat or injure smaller tank mates