Can cardinal tetras live with peacock cichlids?

Verdict
No

No. Cardinal tetras and peacock cichlids should not share a tank. Different water: cardinal tetras want pH 4.6–7, peacock cichlids want pH 7.8–8.6.

Cardinal tetraCardinal tetra76–84°F · pH 4.6–7 Peacock cichlidPeacock cichlid76–82°F · pH 7.8–8.6

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Both: 76–82°Cardinal tetra 76–84°Peacock cichlid 76–82°
The green band is the temperature range both can live in.
456789Cardinal tetra 4.6–7Peacock cichlid 7.8–8.6
No pH suits both. One would live in the wrong water all the time.

Size to scale

Cardinal tetra · 2 inPeacock cichlid · 6 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 tetraPeacock cichlid
Temperature76–84 °F76–82 °F
pH4.6–77.8–8.6
Adult size2.0 in6.0 in
Minimum tank20 gal55 gal
TemperamentPeacefulSemi-aggressive
Swims atMiddleMiddle
GroupGroups of 6+Groups of 4+
DietOmnivoreCarnivore

Better tank mates for cardinal tetras

All cardinal tetra tank mates

Better tank mates for peacock cichlids

All peacock cichlid tank mates

Questions

Can cardinal tetras live with peacock cichlids?

No. Cardinal tetras and peacock cichlids should not share a tank. Different water: cardinal tetras want pH 4.6–7, peacock cichlids want pH 7.8–8.6.

What temperature suits both cardinal tetras and peacock cichlids?

76–82 °F. Cardinal tetras need 76–84 °F, peacock cichlids need 76–82 °F.

What size tank do cardinal tetras and peacock cichlids need together?

At least 55 gal, set by the peacock cichlid. Add space for each extra fish.