Coral Red Pencilfish (Nannostomus sp.) in a freshwater aquarium
Varies carePeacefulSchool of 6+South America

Coral Red Pencilfish

Nannostomus sp.

The Coral Red Pencilfish (Nannostomus sp.) is a peaceful fish that's rewarding to keep. Give it a tank of at least 55 litres (15 US gallons), water held at 75-82°F, and a pH of 6.5-7.5. Always keep a group of at least 6 - they feel safest in numbers.

Care levelVaries
TemperamentPeaceful
Min tank size14.5 US gal
pH range6.5-7.5
Temperature75-82°F
Max size1.2 in (3.0 cm)
Captive lifespan5-10 years
SchoolingYes · 6+ 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

South America

  • South America

Regional colours match the stocking calculator's origin map.

Coral Red Pencilfish Tank Setup

A tank of at least 55 litres (15 US gallons) works well. Keep the water at 75-82°F with a pH around 6.5-7.5, and set up both cover and open swimming space where they spend most of their time (Mid). Always keep a group of at least 6 of their own kind - kept alone or in pairs they tend to turn shy, nippy, or wash out in colour.

What Do Coral Red Pencilfish Eat?

They're not fussy eaters - feed a varied diet, rotating good-quality dry, frozen, and gel foods rather than the same thing every day, and match the food size to their mouths.

Coral Red Pencilfish Tank Mates

The Coral Red Pencilfish 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 6 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 Coral Red Pencilfish Good for Beginners?

Care demand varies by line and setup. Match the care level to how often you actually test and change water.

Coral Red Pencilfish - frequently asked questions

What size tank do Coral Red Pencilfish need?

Coral Red Pencilfish need a tank of at least 55 litres (15 US gallons). A bigger tank is always easier to keep stable, and gives them more room to settle in and behave naturally.

How many Coral Red Pencilfish should I keep together?

Keep a group of at least 6. Coral Red Pencilfish are a shoaling species and become stressed, lose their colour, or hide when kept singly or in pairs.

What water parameters do Coral Red Pencilfish need?

Keep them at 75-82°F with a pH of 6.5-7.5, 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 Coral Red Pencilfish eat?

Coral Red Pencilfish are omnivores and aren't fussy eaters. Feed a varied mix of good-quality dry, frozen, and gel foods, and match the food size to their mouths. Feed small amounts once or twice a day, and remove anything they don't eat.

Are Coral Red Pencilfish good for beginners?

It depends on the setup. Match Coral Red Pencilfish to how often you actually test water and perform maintenance.

Common mistakes with Coral Red Pencilfish

  • Buying fewer than 6 - Coral Red Pencilfishs 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 Coral Red Pencilfish

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
  • Common GoldfishGoldfish - prefer cooler, harder water that tropical fish cannot tolerate