Can congo tetras live with boesemani rainbowfish?

Verdict
Yes

Yes. Congo tetras and boesemani rainbowfish make a good pair. Both are fine at 75–82°F. Plan on at least 30 gal.

Congo tetraCongo tetra73–82°F · pH 6–7.5 Boesemani rainbowfishBoesemani rainbowfish75–82°F · pH 7–8

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–82°Congo tetra 73–82°Boesemani rainbowfish 75–82°
The green band is the temperature range both can live in.
456789Both: 7–7.5Congo tetra 6–7.5Boesemani rainbowfish 7–8
The green band is the pH both tolerate.

Size to scale

Congo tetra · 3 inBoesemani rainbowfish · 4 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 tetraBoesemani rainbowfish
Temperature73–82 °F75–82 °F
pH6–7.57–8
Adult size3.0 in4.0 in
Minimum tank30 gal30 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 boesemani rainbowfish

All boesemani rainbowfish tank mates

Questions

Can congo tetras live with boesemani rainbowfish?

Yes. Congo tetras and boesemani rainbowfish make a good pair. Both are fine at 75–82°F. Plan on at least 30 gal.

What temperature suits both congo tetras and boesemani rainbowfish?

75–82 °F. Congo tetras need 73–82 °F, boesemani rainbowfish need 75–82 °F.

What size tank do congo tetras and boesemani rainbowfish need together?

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