Can guppies live with hatchetfish?

Verdict
Yes

Yes. Guppies and hatchetfish make a good pair. Both are fine at 75–81°F. Plan on at least 20 gal.

GuppyGuppy72–82°F · pH 6.8–7.8 HatchetfishHatchetfish75–81°F · pH 5.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–81°Guppy 72–82°Hatchetfish 75–81°
The green band is the temperature range both can live in.
456789Both: 6.8–7.5Guppy 6.8–7.8Hatchetfish 5.5–7.5
The green band is the pH both tolerate.

Size to scale

Guppy · 2 inHatchetfish · 1.5 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

GuppyHatchetfish
Temperature72–82 °F75–81 °F
pH6.8–7.85.5–7.5
Adult size2.0 in1.5 in
Minimum tank10 gal20 gal
TemperamentPeacefulPeaceful
Swims atTopTop
GroupGroups of 3+Groups of 6+
DietOmnivoreCarnivore

Better tank mates for guppies

All guppy tank mates

Better tank mates for hatchetfish

All hatchetfish tank mates

Questions

Can guppies live with hatchetfish?

Yes. Guppies and hatchetfish make a good pair. Both are fine at 75–81°F. Plan on at least 20 gal.

What temperature suits both guppies and hatchetfish?

75–81 °F. Guppies need 72–82 °F, hatchetfish need 75–81 °F.

What size tank do guppies and hatchetfish need together?

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