Can bristlenose plecos live with upside down catfish?

Verdict
Yes

Yes, bristlenose plecos and upside down catfish can live together. Both are fine at 73–79°F. Plan on at least 30 gal.

Bristlenose plecoBristlenose pleco73–81°F · pH 6.5–7.5 Upside down catfishUpside down catfish72–79°F · pH 6–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–79°Bristlenose pleco 73–81°Upside down catfish 72–79°
The green band is the temperature range both can live in.
456789Both: 6.5–7.5Bristlenose pleco 6.5–7.5Upside down catfish 6–7.5
The green band is the pH both tolerate.

Size to scale

Bristlenose pleco · 5 inUpside down catfish · 4 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

Bristlenose plecoUpside down catfish
Temperature73–81 °F72–79 °F
pH6.5–7.56–7.5
Adult size5.0 in4.0 in
Minimum tank30 gal30 gal
TemperamentPeacefulPeaceful
Swims atBottomBottom
GroupAlone or in pairsGroups of 3+
DietHerbivoreOmnivore

Better tank mates for bristlenose plecos

All bristlenose pleco tank mates

Better tank mates for upside down catfish

All upside down catfish tank mates

Questions

Can bristlenose plecos live with upside down catfish?

Yes, bristlenose plecos and upside down catfish can live together. Both are fine at 73–79°F. Plan on at least 30 gal.

What temperature suits both bristlenose plecos and upside down catfish?

73–79 °F. Bristlenose plecos need 73–81 °F, upside down catfish need 72–79 °F.

What size tank do bristlenose plecos and upside down catfish need together?

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