Can ember tetras live with black skirt tetras?

Verdict
Yes

Yes. Ember tetras and black skirt tetras make a good pair. Both are fine at 73–80°F. Plan on at least 15 gal.

Ember tetraEmber tetra73–84°F · pH 5.5–7 Black skirt tetraBlack skirt tetra70–80°F · pH 6–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–80°Ember tetra 73–84°Black skirt tetra 70–80°
The green band is the temperature range both can live in.
456789Both: 6–7Ember tetra 5.5–7Black skirt tetra 6–7.5
The green band is the pH both tolerate.

Size to scale

Ember tetra · 0.8 inBlack skirt tetra · 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

Ember tetraBlack skirt tetra
Temperature73–84 °F70–80 °F
pH5.5–76–7.5
Adult size0.8 in2.5 in
Minimum tank5 gal15 gal
TemperamentPeacefulSemi-aggressive
Swims atMiddleMiddle
GroupGroups of 6+Groups of 6+
DietOmnivoreOmnivore

Better tank mates for ember tetras

All ember tetra tank mates

Better tank mates for black skirt tetras

All black skirt tetra tank mates

Questions

Can ember tetras live with black skirt tetras?

Yes. Ember tetras and black skirt tetras make a good pair. Both are fine at 73–80°F. Plan on at least 15 gal.

What temperature suits both ember tetras and black skirt tetras?

73–80 °F. Ember tetras need 73–84 °F, black skirt tetras need 70–80 °F.

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

At least 15 gal, set by the black skirt tetra. Add space for each extra fish.