Species profile
Three-lined Pencilfish
Nannostomus trifasciatusThree-lined Pencilfish (Nannostomus trifasciatus) is a schooling community species for a cycled 20+ gallon freshwater aquarium. Plan for about 2.2 inches as an adult, 74-82°F water, pH 5.5-7.2, and moderate care. Keep a group of at least 6; larger groups often behave more naturally when the tank has room.
Community leaningModerate care
20 galMinimum tank
2.2 inAdult size
6Schooling minimum
74-82°FTemperature
Water Range
- pH
- 5.5-7.2
- GH
- 1-10 dGH
- KH
- 1-6 dKH
Behavior
- Temperament
- Peaceful
- Fin nipping
- 0/5
- Territory
- 0/5
Diet and Care
- Diet
- omnivore/micro-predator
- Diet difficulty
- 2/5
- Care difficulty
- 3/5
Planning Notes
Sensitive species; best for stable, mature tanks with consistent water quality.
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