Can serpae tetras live with swordtails?

Verdict
Yes

Yes. Serpae tetras and swordtails get along in the same tank. Both are fine at 72–79°F. Plan on at least 30 gal.

Serpae tetraSerpae tetra72–79°F · pH 6–7.5 SwordtailSwordtail72–79°F · pH 7–8.3

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–79°Serpae tetra 72–79°Swordtail 72–79°
The green band is the temperature range both can live in.
456789Both: 7–7.5Serpae tetra 6–7.5Swordtail 7–8.3
The green band is the pH both tolerate.

Size to scale

Serpae tetra · 1.75 inSwordtail · 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 tetraSwordtail
Temperature72–79 °F72–79 °F
pH6–7.57–8.3
Adult size1.75 in5.0 in
Minimum tank20 gal30 gal
TemperamentSemi-aggressiveSemi-aggressive
Swims atMiddleMiddle
GroupGroups of 6+Groups of 3+
DietOmnivoreOmnivore

Better tank mates for serpae tetras

All serpae tetra tank mates

Better tank mates for swordtails

All swordtail tank mates

Questions

Can serpae tetras live with swordtails?

Yes. Serpae tetras and swordtails get along in the same tank. Both are fine at 72–79°F. Plan on at least 30 gal.

What temperature suits both serpae tetras and swordtails?

72–79 °F. Serpae tetras need 72–79 °F, swordtails need 72–79 °F.

What size tank do serpae tetras and swordtails need together?

At least 30 gal, set by the swordtail. Add space for each extra fish.