Can boesemani rainbowfish live with pencilfish?

Verdict
Yes

Yes, boesemani rainbowfish and pencilfish can live together. Both are fine at 75–82°F. Plan on at least 30 gal.

Boesemani rainbowfishBoesemani rainbowfish75–82°F · pH 7–8 PencilfishPencilfish75–82°F · pH 5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–82°Boesemani rainbowfish 75–82°Pencilfish 75–82°
The green band is the temperature range both can live in.
456789Both: 7–7.5Boesemani rainbowfish 7–8Pencilfish 5–7.5
The green band is the pH both tolerate.

Size to scale

Boesemani rainbowfish · 4 inPencilfish · 2 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

Boesemani rainbowfishPencilfish
Temperature75–82 °F75–82 °F
pH7–85–7.5
Adult size4.0 in2.0 in
Minimum tank30 gal15 gal
TemperamentPeacefulPeaceful
Swims atMiddleMiddle
GroupGroups of 6+Groups of 6+
DietOmnivoreOmnivore

Better tank mates for boesemani rainbowfish

All boesemani rainbowfish tank mates

Better tank mates for pencilfish

All pencilfish tank mates

Questions

Can boesemani rainbowfish live with pencilfish?

Yes, boesemani rainbowfish and pencilfish can live together. Both are fine at 75–82°F. Plan on at least 30 gal.

What temperature suits both boesemani rainbowfish and pencilfish?

75–82 °F. Boesemani rainbowfish need 75–82 °F, pencilfish need 75–82 °F.

What size tank do boesemani rainbowfish and pencilfish need together?

At least 30 gal, set by the boesemani rainbowfish. Add space for each extra fish.