Can discus live with rummy nose tetras?

Verdict
Yes

Yes. Discus and rummy nose tetras get along in the same tank. Both are fine at 82–84°F. Plan on at least 55 gal.

DiscusDiscus82–88°F · pH 5.5–7 Rummy nose tetraRummy nose tetra75–84°F · pH 5.5–7

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 82–84°Discus 82–88°Rummy nose tetra 75–84°
The green band is the temperature range both can live in.
456789Both: 5.5–7Discus 5.5–7Rummy nose tetra 5.5–7
The green band is the pH both tolerate.

Size to scale

Discus · 6 inRummy nose tetra · 2 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

DiscusRummy nose tetra
Temperature82–88 °F75–84 °F
pH5.5–75.5–7
Adult size6.0 in2.0 in
Minimum tank55 gal20 gal
TemperamentPeacefulPeaceful
Swims atMiddleMiddle
GroupGroups of 5+Groups of 6+
DietCarnivoreOmnivore

Better tank mates for discus

All discus tank mates

Better tank mates for rummy nose tetras

All rummy nose tetra tank mates

Questions

Can discus live with rummy nose tetras?

Yes. Discus and rummy nose tetras get along in the same tank. Both are fine at 82–84°F. Plan on at least 55 gal.

What temperature suits both discus and rummy nose tetras?

82–84 °F. Discus need 82–88 °F, rummy nose tetras need 75–84 °F.

What size tank do discus and rummy nose tetras need together?

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