Can bettas live with lemon tetras?

Verdict
Yes

Yes. Bettas and lemon tetras make a good pair. Both are fine at 76–82°F. Plan on at least 15 gal.

BettaBetta76–82°F · pH 6.5–7.5 Lemon tetraLemon tetra72–82°F · pH 5.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 76–82°Betta 76–82°Lemon tetra 72–82°
The green band is the temperature range both can live in.
456789Both: 6.5–7.5Betta 6.5–7.5Lemon tetra 5.5–7.5
The green band is the pH both tolerate.

Size to scale

Betta · 2.5 inLemon 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

BettaLemon tetra
Temperature76–82 °F72–82 °F
pH6.5–7.55.5–7.5
Adult size2.5 in2.0 in
Minimum tank5 gal15 gal
TemperamentSemi-aggressivePeaceful
Swims atTopMiddle
GroupOne per tankGroups of 6+
DietCarnivoreOmnivore

Better tank mates for bettas

All betta tank mates

Better tank mates for lemon tetras

All lemon tetra tank mates

Questions

Can bettas live with lemon tetras?

Yes. Bettas and lemon tetras make a good pair. Both are fine at 76–82°F. Plan on at least 15 gal.

What temperature suits both bettas and lemon tetras?

76–82 °F. Bettas need 76–82 °F, lemon tetras need 72–82 °F.

What size tank do bettas and lemon tetras need together?

At least 15 gal, set by the lemon tetra. Add space for each extra fish.