Can pencilfish live with zebra loaches?

Verdict
Yes

Yes. Pencilfish and zebra loaches make a good pair. Both are fine at 75–79°F. Plan on at least 30 gal.

PencilfishPencilfish75–82°F · pH 5–7.5 Zebra loachZebra loach73–79°F · pH 6–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–79°Pencilfish 75–82°Zebra loach 73–79°
The green band is the temperature range both can live in.
456789Both: 6–7.5Pencilfish 5–7.5Zebra loach 6–7.5
The green band is the pH both tolerate.

Size to scale

Pencilfish · 2 inZebra loach · 3.5 in0"1"2"3"4"5"6"
Adult length in an aquarium. A fish can swallow anything that fits in its mouth, roughly a third to half its own length for predators.

Care at a glance

PencilfishZebra loach
Temperature75–82 °F73–79 °F
pH5–7.56–7.5
Adult size2.0 in3.5 in
Minimum tank15 gal30 gal
TemperamentPeacefulPeaceful
Swims atMiddleBottom
GroupGroups of 6+Groups of 5+
DietOmnivoreOmnivore

Better tank mates for pencilfish

All pencilfish tank mates

Better tank mates for zebra loaches

All zebra loach tank mates

Questions

Can pencilfish live with zebra loaches?

Yes. Pencilfish and zebra loaches make a good pair. Both are fine at 75–79°F. Plan on at least 30 gal.

What temperature suits both pencilfish and zebra loaches?

75–79 °F. Pencilfish need 75–82 °F, zebra loaches need 73–79 °F.

What size tank do pencilfish and zebra loaches need together?

At least 30 gal, set by the zebra loach. Add space for each extra fish.