Can clown loaches live with upside down catfish?

Verdict
Yes

Yes, clown loaches and upside down catfish can live together. Both are fine at 77–79°F. Plan on at least 75 gal.

Clown loachClown loach77–86°F · pH 6–7.5 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: 77–79°Clown loach 77–86°Upside down catfish 72–79°
The green band is the temperature range both can live in.
456789Both: 6–7.5Clown loach 6–7.5Upside down catfish 6–7.5
The green band is the pH both tolerate.

Size to scale

Clown loach · 8 inUpside down catfish · 4 in0"1"2"3"4"5"6"7"8"
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

Clown loachUpside down catfish
Temperature77–86 °F72–79 °F
pH6–7.56–7.5
Adult size8.0 in4.0 in
Minimum tank75 gal30 gal
TemperamentPeacefulPeaceful
Swims atBottomBottom
GroupGroups of 5+Groups of 3+
DietOmnivoreOmnivore

Better tank mates for clown loaches

All clown loach tank mates

Better tank mates for upside down catfish

All upside down catfish tank mates

Questions

Can clown loaches live with upside down catfish?

Yes, clown loaches and upside down catfish can live together. Both are fine at 77–79°F. Plan on at least 75 gal.

What temperature suits both clown loaches and upside down catfish?

77–79 °F. Clown loaches need 77–86 °F, upside down catfish need 72–79 °F.

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

At least 75 gal, set by the clown loach. Add space for each extra fish.