Can discus live with upside down catfish?

Verdict
No

No. Discus and upside down catfish should not share a tank. No shared temperature. Discus need 82–88°F, upside down catfish need 72–79°F.

DiscusDiscus82–88°F · pH 5.5–7 Upside down catfishUpside down catfish72–79°F · pH 6–7.5

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Discus 82–88°Upside down catfish 72–79°
The ranges do not meet, so one of them would always be too warm or too cold.
456789Both: 6–7Discus 5.5–7Upside down catfish 6–7.5
The green band is the pH both tolerate.

Size to scale

Discus · 6 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

DiscusUpside down catfish
Temperature82–88 °F72–79 °F
pH5.5–76–7.5
Adult size6.0 in4.0 in
Minimum tank55 gal30 gal
TemperamentPeacefulPeaceful
Swims atMiddleBottom
GroupGroups of 5+Groups of 3+
DietCarnivoreOmnivore

Better tank mates for discus

All discus tank mates

Better tank mates for upside down catfish

All upside down catfish tank mates

Questions

Can discus live with upside down catfish?

No. Discus and upside down catfish should not share a tank. No shared temperature. Discus need 82–88°F, upside down catfish need 72–79°F.

What temperature suits both discus and upside down catfish?

None. Discus need 82–88 °F and upside down catfish need 72–79 °F, so the ranges do not meet.

What size tank do discus and upside down catfish need together?

At least 55 gal, set by the discus. Add space for each extra fish.