Can guppies live with congo tetras?

Verdict
Yes

Yes, guppies and congo tetras can live together. Both are fine at 73–82°F. Plan on at least 30 gal.

GuppyGuppy72–82°F · pH 6.8–7.8 Congo tetraCongo tetra73–82°F · pH 6–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–82°Guppy 72–82°Congo tetra 73–82°
The green band is the temperature range both can live in.
456789Both: 6.8–7.5Guppy 6.8–7.8Congo tetra 6–7.5
The green band is the pH both tolerate.

Size to scale

Guppy · 2 inCongo tetra · 3 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

GuppyCongo tetra
Temperature72–82 °F73–82 °F
pH6.8–7.86–7.5
Adult size2.0 in3.0 in
Minimum tank10 gal30 gal
TemperamentPeacefulPeaceful
Swims atTopMiddle
GroupGroups of 3+Groups of 6+
DietOmnivoreOmnivore

Better tank mates for guppies

All guppy tank mates

Better tank mates for congo tetras

All congo tetra tank mates

Questions

Can guppies live with congo tetras?

Yes, guppies and congo tetras can live together. Both are fine at 73–82°F. Plan on at least 30 gal.

What temperature suits both guppies and congo tetras?

73–82 °F. Guppies need 72–82 °F, congo tetras need 73–82 °F.

What size tank do guppies and congo tetras need together?

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