Can hatchetfish live with dwarf neon rainbowfish?

Verdict
Yes

Yes. Hatchetfish and dwarf neon rainbowfish get along in the same tank. Both are fine at 75–81°F. Plan on at least 20 gal.

HatchetfishHatchetfish75–81°F · pH 5.5–7.5 Dwarf neon rainbowfishDwarf neon rainbowfish75–82°F · pH 6.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–81°Hatchetfish 75–81°Dwarf neon rainbowfish 75–82°
The green band is the temperature range both can live in.
456789Both: 6.5–7.5Hatchetfish 5.5–7.5Dwarf neon rainbowfish 6.5–7.5
The green band is the pH both tolerate.

Size to scale

Hatchetfish · 1.5 inDwarf neon rainbowfish · 2.5 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

HatchetfishDwarf neon rainbowfish
Temperature75–81 °F75–82 °F
pH5.5–7.56.5–7.5
Adult size1.5 in2.5 in
Minimum tank20 gal20 gal
TemperamentPeacefulPeaceful
Swims atTopMiddle
GroupGroups of 6+Groups of 6+
DietCarnivoreOmnivore

Better tank mates for hatchetfish

All hatchetfish tank mates

Better tank mates for dwarf neon rainbowfish

All dwarf neon rainbowfish tank mates

Questions

Can hatchetfish live with dwarf neon rainbowfish?

Yes. Hatchetfish and dwarf neon rainbowfish get along in the same tank. Both are fine at 75–81°F. Plan on at least 20 gal.

What temperature suits both hatchetfish and dwarf neon rainbowfish?

75–81 °F. Hatchetfish need 75–81 °F, dwarf neon rainbowfish need 75–82 °F.

What size tank do hatchetfish and dwarf neon rainbowfish need together?

At least 20 gal, set by the hatchetfish. Add space for each extra fish.