Can black skirt tetras live with hatchetfish?

Verdict
Yes

Yes. Black skirt tetras and hatchetfish get along in the same tank. Both are fine at 75–80°F. Plan on at least 20 gal.

Black skirt tetraBlack skirt tetra70–80°F · pH 6–7.5 HatchetfishHatchetfish75–81°F · pH 5.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–80°Black skirt tetra 70–80°Hatchetfish 75–81°
The green band is the temperature range both can live in.
456789Both: 6–7.5Black skirt tetra 6–7.5Hatchetfish 5.5–7.5
The green band is the pH both tolerate.

Size to scale

Black skirt tetra · 2.5 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

Black skirt tetraHatchetfish
Temperature70–80 °F75–81 °F
pH6–7.55.5–7.5
Adult size2.5 in1.5 in
Minimum tank15 gal20 gal
TemperamentSemi-aggressivePeaceful
Swims atMiddleTop
GroupGroups of 6+Groups of 6+
DietOmnivoreCarnivore

Better tank mates for black skirt tetras

All black skirt tetra tank mates

Better tank mates for hatchetfish

All hatchetfish tank mates

Questions

Can black skirt tetras live with hatchetfish?

Yes. Black skirt tetras and hatchetfish get along in the same tank. Both are fine at 75–80°F. Plan on at least 20 gal.

What temperature suits both black skirt tetras and hatchetfish?

75–80 °F. Black skirt tetras need 70–80 °F, hatchetfish need 75–81 °F.

What size tank do black skirt tetras and hatchetfish need together?

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