Can congo tetras live with rummy nose tetras?

Verdict
Yes

Yes. Congo tetras and rummy nose tetras get along in the same tank. Both are fine at 75–82°F. Plan on at least 30 gal.

Congo tetraCongo tetra73–82°F · pH 6–7.5 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: 75–82°Congo tetra 73–82°Rummy nose tetra 75–84°
The green band is the temperature range both can live in.
456789Both: 6–7Congo tetra 6–7.5Rummy nose tetra 5.5–7
The green band is the pH both tolerate.

Size to scale

Congo tetra · 3 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

Congo tetraRummy nose tetra
Temperature73–82 °F75–84 °F
pH6–7.55.5–7
Adult size3.0 in2.0 in
Minimum tank30 gal20 gal
TemperamentPeacefulPeaceful
Swims atMiddleMiddle
GroupGroups of 6+Groups of 6+
DietOmnivoreOmnivore

Better tank mates for congo tetras

All congo tetra tank mates

Better tank mates for rummy nose tetras

All rummy nose tetra tank mates

Questions

Can congo tetras live with rummy nose tetras?

Yes. Congo tetras and rummy nose tetras get along in the same tank. Both are fine at 75–82°F. Plan on at least 30 gal.

What temperature suits both congo tetras and rummy nose tetras?

75–82 °F. Congo tetras need 73–82 °F, rummy nose tetras need 75–84 °F.

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

At least 30 gal, set by the congo tetra. Add space for each extra fish.