One-Lined Pencilfish tank mates
Nannostomus unifasciatus
6 rated pairings from the One-Lined Pencilfish care guide. Compatibility here means water, temperament, tank zone and adult size all line up — the note on each card says why. One-Lined Pencilfish needs at least 10 gallons on its own; every companion adds to that.
Excellent matches
5 · Same water, complementary zones, no conflict.
Neon Tetra
Paracheirodon innesi
10 gal min · 1.5" adult · Peaceful
Similar size, peaceful temperament, and water parameter requirements
Ember Tetra
Hyphessobrycon amandae
10 gal min · 0.8" adult · Peaceful
Comparable nano fish with matching care needs and peaceful behavior
Otocinclus
Otocinclus vittatus
10 gal min · 1.5" adult · Peaceful
Peaceful bottom dweller that won't compete for food or space
Dwarf Hairgrass Mini
Eleocharis pusilla
Provides shelter and natural environment without competing
Java Fern
Microsorum pteropus
Provides essential cover and natural habitat structure
Good matches
1 · Compatible with normal care — watch space and numbers.
Planning this tank?
Run the whole stock list through the calculator — it checks bioload and schooling numbers, not just pairings.