Can platies live with serpae tetras?

Verdict
Yes

Yes. Platies and serpae tetras make a good pair. Both are fine at 72–79°F. Plan on at least 20 gal.

PlatyPlaty70–80°F · pH 7–8.2 Serpae tetraSerpae tetra72–79°F · pH 6–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–79°Platy 70–80°Serpae tetra 72–79°
The green band is the temperature range both can live in.
456789Both: 7–7.5Platy 7–8.2Serpae tetra 6–7.5
The green band is the pH both tolerate.

Size to scale

Platy · 2.5 inSerpae tetra · 1.75 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

PlatySerpae tetra
Temperature70–80 °F72–79 °F
pH7–8.26–7.5
Adult size2.5 in1.75 in
Minimum tank10 gal20 gal
TemperamentPeacefulSemi-aggressive
Swims atMiddleMiddle
GroupGroups of 3+Groups of 6+
DietOmnivoreOmnivore

Better tank mates for platies

All platy tank mates

Better tank mates for serpae tetras

All serpae tetra tank mates

Questions

Can platies live with serpae tetras?

Yes. Platies and serpae tetras make a good pair. Both are fine at 72–79°F. Plan on at least 20 gal.

What temperature suits both platies and serpae tetras?

72–79 °F. Platies need 70–80 °F, serpae tetras need 72–79 °F.

What size tank do platies and serpae tetras need together?

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