Can platies live with black neon tetras?

Verdict
Yes

Yes, platies and black neon tetras can live together. Both are fine at 73–80°F. Plan on at least 15 gal.

PlatyPlaty70–80°F · pH 7–8.2 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: 73–80°Platy 70–80°Black neon tetra 73–81°
The green band is the temperature range both can live in.
456789Both: 7–7.5Platy 7–8.2Black neon tetra 5.5–7.5
The green band is the pH both tolerate.

Size to scale

Platy · 2.5 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

PlatyBlack neon tetra
Temperature70–80 °F73–81 °F
pH7–8.25.5–7.5
Adult size2.5 in1.5 in
Minimum tank10 gal15 gal
TemperamentPeacefulPeaceful
Swims atMiddleMiddle
GroupGroups of 3+Groups of 6+
DietOmnivoreOmnivore

Better tank mates for platies

All platy tank mates

Better tank mates for black neon tetras

All black neon tetra tank mates

Questions

Can platies live with black neon tetras?

Yes, platies and black neon tetras can live together. Both are fine at 73–80°F. Plan on at least 15 gal.

What temperature suits both platies and black neon tetras?

73–80 °F. Platies need 70–80 °F, black neon tetras need 73–81 °F.

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

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