Can guppies live with bristlenose plecos?

Verdict
Yes

Yes. Guppies and bristlenose plecos get along in the same tank. Both are fine at 73–81°F. Plan on at least 30 gal.

GuppyGuppy72–82°F · pH 6.8–7.8 Bristlenose plecoBristlenose pleco73–81°F · pH 6.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–81°Guppy 72–82°Bristlenose pleco 73–81°
The green band is the temperature range both can live in.
456789Both: 6.8–7.5Guppy 6.8–7.8Bristlenose pleco 6.5–7.5
The green band is the pH both tolerate.

Size to scale

Guppy · 2 inBristlenose pleco · 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

GuppyBristlenose pleco
Temperature72–82 °F73–81 °F
pH6.8–7.86.5–7.5
Adult size2.0 in5.0 in
Minimum tank10 gal30 gal
TemperamentPeacefulPeaceful
Swims atTopBottom
GroupGroups of 3+Alone or in pairs
DietOmnivoreHerbivore

Better tank mates for guppies

All guppy tank mates

Better tank mates for bristlenose plecos

All bristlenose pleco tank mates

Questions

Can guppies live with bristlenose plecos?

Yes. Guppies and bristlenose plecos get along in the same tank. Both are fine at 73–81°F. Plan on at least 30 gal.

What temperature suits both guppies and bristlenose plecos?

73–81 °F. Guppies need 72–82 °F, bristlenose plecos need 73–81 °F.

What size tank do guppies and bristlenose plecos need together?

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