Can pencilfish live with dojo loaches?

Verdict
Yes

Yes. Pencilfish and dojo loaches get along in the same tank. Both are fine at 75–77°F. Plan on at least 55 gal.

PencilfishPencilfish75–82°F · pH 5–7.5 Dojo loachDojo loach59–77°F · pH 6.5–8

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–77°Pencilfish 75–82°Dojo loach 59–77°
The green band is the temperature range both can live in.
456789Both: 6.5–7.5Pencilfish 5–7.5Dojo loach 6.5–8
The green band is the pH both tolerate.

Size to scale

Pencilfish · 2 inDojo loach · 6 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

PencilfishDojo loach
Temperature75–82 °F59–77 °F
pH5–7.56.5–8
Adult size2.0 in6.0 in
Minimum tank15 gal55 gal
TemperamentPeacefulPeaceful
Swims atMiddleBottom
GroupGroups of 6+Groups of 3+
DietOmnivoreOmnivore

Better tank mates for pencilfish

All pencilfish tank mates

Better tank mates for dojo loaches

All dojo loach tank mates

Questions

Can pencilfish live with dojo loaches?

Yes. Pencilfish and dojo loaches get along in the same tank. Both are fine at 75–77°F. Plan on at least 55 gal.

What temperature suits both pencilfish and dojo loaches?

75–77 °F. Pencilfish need 75–82 °F, dojo loaches need 59–77 °F.

What size tank do pencilfish and dojo loaches need together?

At least 55 gal, set by the dojo loach. Add space for each extra fish.