CheckMyFishTankThree Line Pencilfish care
Nannostomus trifasciatus · Freshwater · Intermediate level care
A slim, peaceful fish for calm planted tanks.
Feeding
Twice a day. A small pinch they finish in about 2 minutes. Micro pellets, baby brine shrimp, crushed flakes.
Good tank mates
Fish that pass every check with Three Line Pencilfish in a 40 gallon tank: same water, overlapping temperature, nobody gets eaten and no bullies.
Do not mix with
- Silver Dollar: Silver Dollar grows big enough to eat Three Line Pencilfish.
- Tinfoil Barb: Tinfoil Barb grows big enough to eat Three Line Pencilfish.
- White Cloud Mountain Minnow: White Cloud Mountain Minnow and Three Line Pencilfish need different water temperatures.
- Angelfish: Angelfish grows big enough to eat Three Line Pencilfish.
- Convict Cichlid: Convict Cichlid grows big enough to eat Three Line Pencilfish.
- Oscar: Oscar grows big enough to eat Three Line Pencilfish.
- Jack Dempsey: Jack Dempsey grows big enough to eat Three Line Pencilfish.
- Firemouth Cichlid: Firemouth Cichlid grows big enough to eat Three Line Pencilfish.
Questions
What size tank does a Three Line Pencilfish need?
At least 20 gallons for a group of 8. Adults grow to about 2 inches, so plan for the adult size, not the size at the store.
What temperature does a Three Line Pencilfish like?
75 to 82 degrees Fahrenheit, with a pH of about 5.5 to 7. A steady temperature matters more than hitting one exact number.
How many Three Line Pencilfish should I keep together?
Keep 8 or more. They feel safe in a group and show better color and behavior.
What do Three Line Pencilfish eat?
Micro pellets, baby brine shrimp, crushed flakes. Feed twice a day: a small pinch they finish in about 2 minutes.
Sources
Checked against these sources on 2026-11-10. When sources disagree we use the safer number.