Can cardinal tetras live with clown plecos?

Verdict
Yes

Yes, cardinal tetras and clown plecos can live together. Both are fine at 76–82°F. Plan on at least 20 gal.

Cardinal tetraCardinal tetra76–84°F · pH 4.6–7 Clown plecoClown pleco73–82°F · pH 6.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 76–82°Cardinal tetra 76–84°Clown pleco 73–82°
The green band is the temperature range both can live in.
456789Both: 6.5–7Cardinal tetra 4.6–7Clown pleco 6.5–7.5
The green band is the pH both tolerate.

Size to scale

Cardinal tetra · 2 inClown pleco · 3.5 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

Cardinal tetraClown pleco
Temperature76–84 °F73–82 °F
pH4.6–76.5–7.5
Adult size2.0 in3.5 in
Minimum tank20 gal20 gal
TemperamentPeacefulPeaceful
Swims atMiddleBottom
GroupGroups of 6+Alone or in pairs
DietOmnivoreHerbivore

Better tank mates for cardinal tetras

All cardinal tetra tank mates

Better tank mates for clown plecos

All clown pleco tank mates

Questions

Can cardinal tetras live with clown plecos?

Yes, cardinal tetras and clown plecos can live together. Both are fine at 76–82°F. Plan on at least 20 gal.

What temperature suits both cardinal tetras and clown plecos?

76–82 °F. Cardinal tetras need 76–84 °F, clown plecos need 73–82 °F.

What size tank do cardinal tetras and clown plecos need together?

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