Can rummy nose tetras live with dwarf neon rainbowfish?

Verdict
Yes

Yes. Rummy nose tetras and dwarf neon rainbowfish get along in the same tank. Both are fine at 75–82°F. Plan on at least 20 gal.

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–82°Rummy nose tetra 75–84°Dwarf neon rainbowfish 75–82°
The green band is the temperature range both can live in.
456789Both: 6.5–7Rummy nose tetra 5.5–7Dwarf neon rainbowfish 6.5–7.5
The green band is the pH both tolerate.

Size to scale

Rummy nose tetra · 2 inDwarf neon rainbowfish · 2.5 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

Rummy nose tetraDwarf neon rainbowfish
Temperature75–84 °F75–82 °F
pH5.5–76.5–7.5
Adult size2.0 in2.5 in
Minimum tank20 gal20 gal
TemperamentPeacefulPeaceful
Swims atMiddleMiddle
GroupGroups of 6+Groups of 6+
DietOmnivoreOmnivore

Better tank mates for rummy nose tetras

All rummy nose tetra tank mates

Better tank mates for dwarf neon rainbowfish

All dwarf neon rainbowfish tank mates

Questions

Can rummy nose tetras live with dwarf neon rainbowfish?

Yes. Rummy nose tetras and dwarf neon rainbowfish get along in the same tank. Both are fine at 75–82°F. Plan on at least 20 gal.

What temperature suits both rummy nose tetras and dwarf neon rainbowfish?

75–82 °F. Rummy nose tetras need 75–84 °F, dwarf neon rainbowfish need 75–82 °F.

What size tank do rummy nose tetras and dwarf neon rainbowfish need together?

At least 20 gal, set by the rummy nose tetra. Add space for each extra fish.