What size tank do golden pencilfish need?
At least 15 gallons (57 liters) for a group of 6. The smallest standard tank that works is the 15 gallon. A bigger tank is always easier to keep stable. We give the size for an adult fish in a proper group, because the small fish in the shop will grow. Scientific name: Nannostomus beckfordi.
How many golden pencilfish in each tank size?
This is how many each standard tank carries comfortably if golden pencilfish are the only fish in it. Share the tank with other species and the number goes down.
| Tank | How many golden pencilfish |
|---|---|
| 5 gallon | Too small |
| 10 gallon | Too small |
| 20 gallon long | up to 11 |
| 29 gallon | up to 16 |
| 40 gallon breeder | up to 22 |
| 55 gallon | up to 31 |
| 75 gallon | up to 43 |
| 125 gallon | 60 or more |
Check golden pencilfish against your own tank and other fish
Good to know
- Keep at least 6. Alone or in twos and threes, golden pencilfish hide, stop eating well, or pick on each other.
Tank mates for golden pencilfish
These animals like the same water, are a safe size, and have a temper that fits. It is a match on paper: always watch new tankmates for the first week.
- Cardinal tetra
- Glowlight tetra
- Black neon tetra
- Harlequin rasbora
- X-ray tetra
- Rummy-nose tetra
- Lemon tetra
- Cherry barb
Poor matches
- Fancy goldfish: Goldfish do best with other fancy goldfish.
- Oscar: Oscar is aggressive and will bully or kill peaceful fish such as golden pencilfish.
- Molly: They need different water: Golden pencilfish likes a pH of 5.5–7.5, molly likes 7.5–8.5.
Questions and answers
What size tank do golden pencilfish need?
At least 15 gallons (57 liters) for a group of 6. The smallest standard tank that works is the 15 gallon. A bigger tank is always easier to keep stable.
How many golden pencilfish should be kept together?
At least 6. Golden pencilfish are social animals and only behave naturally in a group. More is better if the tank has room.
Can golden pencilfish live in a 10 gallon tank?
No. Golden pencilfish needs at least 15 gallons (57 liters).
What temperature do golden pencilfish need?
75–81 °F (24–27 °C), with a pH of 5.5–7.5. In most homes that means a heater.
Can golden pencilfish live with a betta?
Usually, yes, in a tank of 15 gallons (57 liters) or more. They like the same water: 75–81 °F (24–27 °C). Every betta has its own temper, so watch closely for the first week and have a spare tank ready.
More fish
Adult size, tank size and water ranges follow the mainstream care consensus (Seriously Fish species profiles and FishBase maximum lengths). Where sources differ we use the more cautious figure. Stocking numbers come from our stocking calculator.