Can ember tetras live with black neon tetras?

Verdict
Yes

Yes. Ember tetras and black neon tetras get along in the same tank. Both are fine at 73–81°F. Plan on at least 15 gal.

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–81°Ember tetra 73–84°Black neon tetra 73–81°
The green band is the temperature range both can live in.
456789Both: 5.5–7Ember tetra 5.5–7Black neon tetra 5.5–7.5
The green band is the pH both tolerate.

Size to scale

Ember tetra · 0.8 inBlack neon tetra · 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

Ember tetraBlack neon tetra
Temperature73–84 °F73–81 °F
pH5.5–75.5–7.5
Adult size0.8 in1.5 in
Minimum tank5 gal15 gal
TemperamentPeacefulPeaceful
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 neon tetras

All black neon tetra tank mates

Questions

Can ember tetras live with black neon tetras?

Yes. Ember tetras and black neon tetras get along in the same tank. Both are fine at 73–81°F. Plan on at least 15 gal.

What temperature suits both ember tetras and black neon tetras?

73–81 °F. Ember tetras need 73–84 °F, black neon tetras need 73–81 °F.

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

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