Can cardinal tetras live with silver dollars?

Verdict
Yes

Yes, cardinal tetras and silver dollars can live together. Both are fine at 76–82°F. Plan on at least 75 gal.

Cardinal tetraCardinal tetra76–84°F · pH 4.6–7 Silver dollarSilver dollar75–82°F · pH 5–7

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 76–82°Cardinal tetra 76–84°Silver dollar 75–82°
The green band is the temperature range both can live in.
456789Both: 5–7Cardinal tetra 4.6–7Silver dollar 5–7
The green band is the pH both tolerate.

Size to scale

Cardinal tetra · 2 inSilver dollar · 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 tetraSilver dollar
Temperature76–84 °F75–82 °F
pH4.6–75–7
Adult size2.0 in6.0 in
Minimum tank20 gal75 gal
TemperamentPeacefulPeaceful
Swims atMiddleMiddle
GroupGroups of 6+Groups of 5+
DietOmnivoreHerbivore

Better tank mates for cardinal tetras

All cardinal tetra tank mates

Better tank mates for silver dollars

All silver dollar tank mates

Questions

Can cardinal tetras live with silver dollars?

Yes, cardinal tetras and silver dollars can live together. Both are fine at 76–82°F. Plan on at least 75 gal.

What temperature suits both cardinal tetras and silver dollars?

76–82 °F. Cardinal tetras need 76–84 °F, silver dollars need 75–82 °F.

What size tank do cardinal tetras and silver dollars need together?

At least 75 gal, set by the silver dollar. Add space for each extra fish.