Can otocinclus live with congo tetras?

Verdict
Yes

Yes, otocinclus and congo tetras can live together. Both are fine at 73–79°F. Plan on at least 30 gal.

OtocinclusOtocinclus72–79°F · pH 6–7.5 Congo tetraCongo tetra73–82°F · pH 6–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–79°Otocinclus 72–79°Congo tetra 73–82°
The green band is the temperature range both can live in.
456789Both: 6–7.5Otocinclus 6–7.5Congo tetra 6–7.5
The green band is the pH both tolerate.

Size to scale

Otocinclus · 2 inCongo tetra · 3 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

OtocinclusCongo tetra
Temperature72–79 °F73–82 °F
pH6–7.56–7.5
Adult size2.0 in3.0 in
Minimum tank20 gal30 gal
TemperamentPeacefulPeaceful
Swims atBottomMiddle
GroupGroups of 6+Groups of 6+
DietHerbivoreOmnivore

Better tank mates for otocinclus

All otocinclus tank mates

Better tank mates for congo tetras

All congo tetra tank mates

Questions

Can otocinclus live with congo tetras?

Yes, otocinclus and congo tetras can live together. Both are fine at 73–79°F. Plan on at least 30 gal.

What temperature suits both otocinclus and congo tetras?

73–79 °F. Otocinclus need 72–79 °F, congo tetras need 73–82 °F.

What size tank do otocinclus and congo tetras need together?

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