Can otocinclus live with black skirt tetras?

Verdict
Yes

Yes, otocinclus and black skirt tetras can live together. Both are fine at 72–79°F. Plan on at least 20 gal.

OtocinclusOtocinclus72–79°F · pH 6–7.5 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: 72–79°Otocinclus 72–79°Black skirt tetra 70–80°
The green band is the temperature range both can live in.
456789Both: 6–7.5Otocinclus 6–7.5Black skirt tetra 6–7.5
The green band is the pH both tolerate.

Size to scale

Otocinclus · 2 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

OtocinclusBlack skirt tetra
Temperature72–79 °F70–80 °F
pH6–7.56–7.5
Adult size2.0 in2.5 in
Minimum tank20 gal15 gal
TemperamentPeacefulSemi-aggressive
Swims atBottomMiddle
GroupGroups of 6+Groups of 6+
DietHerbivoreOmnivore

Better tank mates for otocinclus

All otocinclus tank mates

Better tank mates for black skirt tetras

All black skirt tetra tank mates

Questions

Can otocinclus live with black skirt tetras?

Yes, otocinclus and black skirt tetras can live together. Both are fine at 72–79°F. Plan on at least 20 gal.

What temperature suits both otocinclus and black skirt tetras?

72–79 °F. Otocinclus need 72–79 °F, black skirt tetras need 70–80 °F.

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

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