Dwarf Pencilfish
Nannostomus sp.
The Dwarf Pencilfish (Nannostomus sp.) is a peaceful fish that's rewarding to keep. Give it a tank of at least 45 litres (12 US gallons), water held at 72-82°F, and a pH of 6.5-7.5.
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.
Dwarf Pencilfish Tank Setup
A tank of at least 45 litres (12 US gallons) works well. Keep the water at 72-82°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).
What Do Dwarf 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.
Dwarf Pencilfish Tank Mates
The Dwarf Pencilfish is peaceful, which is the first thing to weigh up when you choose tank mates. Good matches come down to the whole stocking list working together - temperature, tank size, and temperament - not any single label. 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 Dwarf Pencilfish Good for Beginners?
Care demand varies by line and setup. Match the care level to how often you actually test and change water.
Dwarf Pencilfish - frequently asked questions
What size tank do Dwarf Pencilfish need?
Dwarf Pencilfish need a tank of at least 45 litres (12 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 Dwarf Pencilfish need?
Keep them at 72-82°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 Dwarf Pencilfish eat?
Dwarf 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 Dwarf Pencilfish good for beginners?
It depends on the setup. Match Dwarf Pencilfish to how often you actually test water and perform maintenance.
Building a community? Run the full list through the stocking calculator before you add anything else.
Great tank mates
Chosen from temperament, overlapping temperature/pH bands, plausible minimum tank footprints, and size versus yours in App-aquatic data. Hobby nuance always wins - verify stocking and temperament before purchasing.
Fish to avoid mixing with Dwarf 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
- Betta (Male)Predator - Betta (Male) will eat or injure smaller tank mates
