Can platies live with black skirt tetras?

Verdict
Yes

Yes, platies and black skirt tetras can live together. Both are fine at 70–80°F. Plan on at least 15 gal.

PlatyPlaty70–80°F · pH 7–8.2 Black skirt tetraBlack skirt tetra70–80°F · pH 6–7.5

Why it works

Water side by side

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

Size to scale

Platy · 2.5 inBlack skirt tetra · 2.5 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 skirt tetra
Temperature70–80 °F70–80 °F
pH7–8.26–7.5
Adult size2.5 in2.5 in
Minimum tank10 gal15 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 black skirt tetras

All black skirt tetra tank mates

Questions

Can platies live with black skirt tetras?

Yes, platies and black skirt tetras can live together. Both are fine at 70–80°F. Plan on at least 15 gal.

What temperature suits both platies and black skirt tetras?

70–80 °F. Platies need 70–80 °F, black skirt tetras need 70–80 °F.

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

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