Can fancy goldfish live with clown plecos?

Verdict
No

No. Fancy goldfish and clown plecos should not share a tank. Fancy goldfish are coldwater animals (65–74°F); clown plecos need 73–82°F. They overlap only at 73–74°F, the edge of both ranges.

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–74°Fancy goldfish 65–74°Clown pleco 73–82°
The green band is the temperature range both can live in.
456789Both: 7–7.5Fancy goldfish 7–8Clown pleco 6.5–7.5
The green band is the pH both tolerate.

Size to scale

Fancy goldfish · 6 inClown pleco · 3.5 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 goldfishClown pleco
Temperature65–74 °F73–82 °F
pH7–86.5–7.5
Adult size6.0 in3.5 in
Minimum tank30 gal20 gal
TemperamentPeacefulPeaceful
Swims atAll levelsBottom
GroupAlone or in pairsAlone or in pairs
DietOmnivoreHerbivore

Better tank mates for fancy goldfish

All fancy goldfish tank mates

Better tank mates for clown plecos

All clown pleco tank mates

Questions

Can fancy goldfish live with clown plecos?

No. Fancy goldfish and clown plecos should not share a tank. Fancy goldfish are coldwater animals (65–74°F); clown plecos need 73–82°F. They overlap only at 73–74°F, the edge of both ranges.

What temperature suits both fancy goldfish and clown plecos?

73–74 °F. Fancy goldfish need 65–74 °F, clown plecos need 73–82 °F.

What size tank do fancy goldfish and clown plecos need together?

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