Can guppies live with ember tetras?

Verdict
Yes

Yes. Guppies and ember tetras get along in the same tank. Both are fine at 73–82°F. Plan on at least 10 gal.

GuppyGuppy72–82°F · pH 6.8–7.8 Ember tetraEmber tetra73–84°F · pH 5.5–7

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–82°Guppy 72–82°Ember tetra 73–84°
The green band is the temperature range both can live in.
456789Both: 6.8–7Guppy 6.8–7.8Ember tetra 5.5–7
The green band is the pH both tolerate.

Size to scale

Guppy · 2 inEmber tetra · 0.8 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

GuppyEmber tetra
Temperature72–82 °F73–84 °F
pH6.8–7.85.5–7
Adult size2.0 in0.8 in
Minimum tank10 gal5 gal
TemperamentPeacefulPeaceful
Swims atTopMiddle
GroupGroups of 3+Groups of 6+
DietOmnivoreOmnivore

Better tank mates for guppies

All guppy tank mates

Better tank mates for ember tetras

All ember tetra tank mates

Questions

Can guppies live with ember tetras?

Yes. Guppies and ember tetras get along in the same tank. Both are fine at 73–82°F. Plan on at least 10 gal.

What temperature suits both guppies and ember tetras?

73–82 °F. Guppies need 72–82 °F, ember tetras need 73–84 °F.

What size tank do guppies and ember tetras need together?

At least 10 gal, set by the guppy. Add space for each extra fish.