Phoenix Rasbora (Boraras merah) in a freshwater aquarium
Intermediate carePeacefulSchool of 8+Southeast Asia

Phoenix Rasbora

Boraras merah

The Phoenix Rasbora (Boraras merah) is a peaceful fish that's a good step up once you have a little experience. Give it a tank of at least 30 litres (8 US gallons), water held at 72-82°F, and a pH of 5.5-7. Always keep a group of at least 8 - they feel safest in numbers.

Care levelIntermediate
TemperamentPeaceful
Min tank size7.9 US gal
pH range5.5-7
Temperature72-82°F
Max size1.0 in (2.5 cm)
Captive lifespan3-6 years
SchoolingYes · 8+ recommended
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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.

Phoenix Rasbora Tank Setup

Give them a tank of at least 30 litres (8 US gallons). As open-water swimmers they care more about swimming length than height, so a longer tank is ideal. Keep the water at 72-82°F with a pH around 5.5-7, and avoid sudden swings. Always keep a group of at least 8 of their own kind - kept alone or in pairs they tend to turn shy, nippy, or wash out in colour.

What Do Phoenix Rasboras 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.

Phoenix Rasbora Tank Mates

Tiny rasbora requiring soft, acidic water. Keep in groups of 8+. May be eaten by anything larger. Nano tank specialist. The Phoenix Rasbora is peaceful, which is the first thing to weigh up when you choose tank mates. It's a shoaling fish, so settle a group of 8 or more of its own kind before adding anything else - a stressed, lonely fish is far more likely to nip or hide. 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 Phoenix Rasboras Good for Beginners?

Doable once you test water regularly and catch problems before fish look sick. If this is your first tank, pick something more forgiving and come back later.

Phoenix Rasbora - frequently asked questions

What size tank do Phoenix Rasboras need?

Phoenix Rasboras need a tank of at least 30 litres (8 US gallons). A bigger tank is always easier to keep stable, and gives them more room to settle in and behave naturally.

How many Phoenix Rasboras should I keep together?

Keep a group of at least 8. Phoenix Rasboras are a shoaling species and become stressed, lose their colour, or hide when kept singly or in pairs.

What water parameters do Phoenix Rasboras need?

Keep them at 72-82°F with a pH of 5.5-7, 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 Phoenix Rasboras eat?

Phoenix Rasboras 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 Phoenix Rasboras good for beginners?

Phoenix Rasboras 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 Phoenix Rasboras

  • Buying fewer than 8 - Phoenix Rasboras need a proper school to feel secure; isolated individuals hide, fail to colour up, or become stressed.

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

Fish to avoid mixing with Phoenix Rasboras

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
  • Betta (Male)Predator - Betta (Male) will eat or injure smaller tank mates