Species · Nannostomus marginatus

Dwarf pencilfish: tank size, water and tank mates

Timid nano; best with small peaceful fish.

Adult size3.5 cm (1.4 in)
Minimum tank10 US gal
Temperature22–28 °C (72–82 °F)
pH5.8–7
Temperamentpeaceful
Keep in groups of10+
Swimsmid
Shrimp & snailsUsually safe

Check a tank with Dwarf pencilfish

Good tank mates for Dwarf pencilfish

These species share its temperature range and temperament, with no fin-nipping or predation risk under our rules. Still check your tank size and bioload in the checker.

African dwarf frog · Amano shrimp · Assassin snail · Banjo catfish · Black neon tetra · Black phantom tetra · Black ruby barb · Bleeding heart tetra · Bloodfin tetra · Boeseman's rainbowfish · Bristlenose pleco · Bronze corydoras · Bumblebee goby · Cardinal tetra · Celestial pearl danio · Checkerboard barb · Cherry barb · Cherry shrimp · Chili rasbora · Clown killifish · Clown pleco · Colombian tetra · Congo tetra · CPO dwarf crayfish

Avoid with Dwarf pencilfish

African butterflyfish (predation) · Banded archerfish (predation) · Black ghost knifefish (predation) · Blue acara (predation) · Common / comet goldfish (temperature) · Convict cichlid (predation) · Demasoni cichlid (aggression) · Fancy goldfish (temperature) · Jack Dempsey (predation) · Jewel cichlid (predation) · Oscar (predation) · Paradise fish (aggression) · Pea puffer (aggression) · Pictus catfish (predation) · Senegal bichir (predation) · Severum (predation) · Striped raphael catfish (predation) · Tinfoil barb (predation)

Sources

Checked 2026-11-09 · confidence: medium. These are cautious community guidelines, not guarantees. Not veterinary advice. Report an error.