Can serpae tetras live with black neon tetras?

Verdict
Yes

Yes. Serpae tetras and black neon tetras make a good pair. Both are fine at 73–79°F. Plan on at least 20 gal.

Serpae tetraSerpae tetra72–79°F · pH 6–7.5 Black neon tetraBlack neon tetra73–81°F · pH 5.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–79°Serpae tetra 72–79°Black neon tetra 73–81°
The green band is the temperature range both can live in.
456789Both: 6–7.5Serpae tetra 6–7.5Black neon tetra 5.5–7.5
The green band is the pH both tolerate.

Size to scale

Serpae tetra · 1.75 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

Serpae tetraBlack neon tetra
Temperature72–79 °F73–81 °F
pH6–7.55.5–7.5
Adult size1.75 in1.5 in
Minimum tank20 gal15 gal
TemperamentSemi-aggressivePeaceful
Swims atMiddleMiddle
GroupGroups of 6+Groups of 6+
DietOmnivoreOmnivore

Better tank mates for serpae tetras

All serpae tetra tank mates

Better tank mates for black neon tetras

All black neon tetra tank mates

Questions

Can serpae tetras live with black neon tetras?

Yes. Serpae tetras and black neon tetras make a good pair. Both are fine at 73–79°F. Plan on at least 20 gal.

What temperature suits both serpae tetras and black neon tetras?

73–79 °F. Serpae tetras need 72–79 °F, black neon tetras need 73–81 °F.

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

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