Can kuhli loaches live with upside down catfish?

Verdict
Yes

Yes. Kuhli loaches and upside down catfish make a good pair. Both are fine at 75–79°F. Plan on at least 30 gal.

Kuhli loachKuhli loach75–86°F · pH 5.5–7 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: 75–79°Kuhli loach 75–86°Upside down catfish 72–79°
The green band is the temperature range both can live in.
456789Both: 6–7Kuhli loach 5.5–7Upside down catfish 6–7.5
The green band is the pH both tolerate.

Size to scale

Kuhli loach · 3.5 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

Kuhli loachUpside down catfish
Temperature75–86 °F72–79 °F
pH5.5–76–7.5
Adult size3.5 in4.0 in
Minimum tank20 gal30 gal
TemperamentPeacefulPeaceful
Swims atBottomBottom
GroupGroups of 6+Groups of 3+
DietOmnivoreOmnivore

Better tank mates for kuhli loaches

All kuhli loach tank mates

Better tank mates for upside down catfish

All upside down catfish tank mates

Questions

Can kuhli loaches live with upside down catfish?

Yes. Kuhli loaches and upside down catfish make a good pair. Both are fine at 75–79°F. Plan on at least 30 gal.

What temperature suits both kuhli loaches and upside down catfish?

75–79 °F. Kuhli loaches need 75–86 °F, upside down catfish need 72–79 °F.

What size tank do kuhli loaches and upside down catfish need together?

At least 30 gal, set by the upside down catfish. Add space for each extra fish.