Can swordtails live with clown plecos?

Verdict
Yes

Yes. Swordtails and clown plecos make a good pair. Both are fine at 73–79°F. Plan on at least 30 gal.

SwordtailSwordtail72–79°F · pH 7–8.3 Clown plecoClown pleco73–82°F · pH 6.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–79°Swordtail 72–79°Clown pleco 73–82°
The green band is the temperature range both can live in.
456789Both: 7–7.5Swordtail 7–8.3Clown pleco 6.5–7.5
The green band is the pH both tolerate.

Size to scale

Swordtail · 5 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

SwordtailClown pleco
Temperature72–79 °F73–82 °F
pH7–8.36.5–7.5
Adult size5.0 in3.5 in
Minimum tank30 gal20 gal
TemperamentSemi-aggressivePeaceful
Swims atMiddleBottom
GroupGroups of 3+Alone or in pairs
DietOmnivoreHerbivore

Better tank mates for swordtails

All swordtail tank mates

Better tank mates for clown plecos

All clown pleco tank mates

Questions

Can swordtails live with clown plecos?

Yes. Swordtails and clown plecos make a good pair. Both are fine at 73–79°F. Plan on at least 30 gal.

What temperature suits both swordtails and clown plecos?

73–79 °F. Swordtails need 72–79 °F, clown plecos need 73–82 °F.

What size tank do swordtails and clown plecos need together?

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