Can fancy goldfish live with lemon tetras?

Verdict
No

No. Fancy goldfish and lemon tetras should not share a tank. Fancy goldfish are coldwater animals (65–74°F); lemon tetras need 72–82°F. They overlap only at 72–74°F, the edge of both ranges.

Fancy goldfishFancy goldfish65–74°F · pH 7–8 Lemon tetraLemon tetra72–82°F · pH 5.5–7.5

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–74°Fancy goldfish 65–74°Lemon tetra 72–82°
The green band is the temperature range both can live in.
456789Both: 7–7.5Fancy goldfish 7–8Lemon tetra 5.5–7.5
The green band is the pH both tolerate.

Size to scale

Fancy goldfish · 6 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

Fancy goldfishLemon tetra
Temperature65–74 °F72–82 °F
pH7–85.5–7.5
Adult size6.0 in2.0 in
Minimum tank30 gal15 gal
TemperamentPeacefulPeaceful
Swims atAll levelsMiddle
GroupAlone or in pairsGroups of 6+
DietOmnivoreOmnivore

Better tank mates for fancy goldfish

All fancy goldfish tank mates

Better tank mates for lemon tetras

All lemon tetra tank mates

Questions

Can fancy goldfish live with lemon tetras?

No. Fancy goldfish and lemon tetras should not share a tank. Fancy goldfish are coldwater animals (65–74°F); lemon tetras need 72–82°F. They overlap only at 72–74°F, the edge of both ranges.

What temperature suits both fancy goldfish and lemon tetras?

72–74 °F. Fancy goldfish need 65–74 °F, lemon tetras need 72–82 °F.

What size tank do fancy goldfish and lemon tetras need together?

At least 30 gal, set by the fancy goldfish. Add space for each extra fish.