Can discus live with pencilfish?

Verdict
Yes, with care

Yes, with care. Discus and pencilfish can share a tank, but watch one thing. They only share 82°F. Keep the heater set there and steady.

DiscusDiscus82–88°F · pH 5.5–7 PencilfishPencilfish75–82°F · pH 5–7.5

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Both: 82°Discus 82–88°Pencilfish 75–82°
The green band is the temperature range both can live in.
456789Both: 5.5–7Discus 5.5–7Pencilfish 5–7.5
The green band is the pH both tolerate.

Size to scale

Discus · 6 inPencilfish · 2 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

DiscusPencilfish
Temperature82–88 °F75–82 °F
pH5.5–75–7.5
Adult size6.0 in2.0 in
Minimum tank55 gal15 gal
TemperamentPeacefulPeaceful
Swims atMiddleMiddle
GroupGroups of 5+Groups of 6+
DietCarnivoreOmnivore

Better tank mates for discus

All discus tank mates

Better tank mates for pencilfish

All pencilfish tank mates

Questions

Can discus live with pencilfish?

Yes, with care. Discus and pencilfish can share a tank, but watch one thing. They only share 82°F. Keep the heater set there and steady.

What temperature suits both discus and pencilfish?

82–82 °F. Discus need 82–88 °F, pencilfish need 75–82 °F.

What size tank do discus and pencilfish need together?

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