Can plecos live with cardinal tetras?

Verdict

Yes, with care

Yes, with care. Plecos and cardinal tetras can share a tank, but watch one thing. Plecos grow to 15 inches and need 125 gallons, far more than a tank set up for cardinal tetras.

Common pleco72–86°F · pH 6.5–7.5

Cardinal tetra76–84°F · pH 4.6–7

What to watch

Watch outPlecos grow to 15 inches and need 125 gallons, far more than a tank set up for cardinal tetras.

What works

Both are fine at 76–84°F.
pH 6.5–7 suits both.
They use different parts of the tank: plecos the bottom, cardinal tetras the mid.

Water side by side

The green band is the temperature range both can live in.

The green band is the pH both tolerate.

Size to scale

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

	Common pleco	Cardinal tetra
Temperature	72–86 °F	76–84 °F
pH	6.5–7.5	4.6–7
Adult size	15.0 in	2.0 in
Minimum tank	125 gal	20 gal
Temperament	Peaceful	Peaceful
Swims at	Bottom	Middle
Group	Alone or in pairs	Groups of 6+
Diet	Herbivore	Omnivore

Better tank mates for plecos

All common pleco tank mates

Better tank mates for cardinal tetras

All cardinal tetra tank mates

Questions

Can plecos live with cardinal tetras?

Yes, with care. Plecos and cardinal tetras can share a tank, but watch one thing. Plecos grow to 15 inches and need 125 gallons, far more than a tank set up for cardinal tetras.

What temperature suits both plecos and cardinal tetras?

76–84 °F. Plecos need 72–86 °F, cardinal tetras need 76–84 °F.

What size tank do plecos and cardinal tetras need together?

At least 125 gal, set by the common pleco. Add space for each extra fish.