Can glass catfish live with pencilfish?

Verdict
Yes

Yes, glass catfish and pencilfish can live together. Both are fine at 75–80°F. Plan on at least 30 gal.

Glass catfishGlass catfish75–80°F · pH 6.5–7.5 PencilfishPencilfish75–82°F · pH 5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–80°Glass catfish 75–80°Pencilfish 75–82°
The green band is the temperature range both can live in.
456789Both: 6.5–7.5Glass catfish 6.5–7.5Pencilfish 5–7.5
The green band is the pH both tolerate.

Size to scale

Glass catfish · 3 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

Glass catfishPencilfish
Temperature75–80 °F75–82 °F
pH6.5–7.55–7.5
Adult size3.0 in2.0 in
Minimum tank30 gal15 gal
TemperamentPeacefulPeaceful
Swims atMiddleMiddle
GroupGroups of 6+Groups of 6+
DietCarnivoreOmnivore

Better tank mates for glass catfish

All glass catfish tank mates

Better tank mates for pencilfish

All pencilfish tank mates

Questions

Can glass catfish live with pencilfish?

Yes, glass catfish and pencilfish can live together. Both are fine at 75–80°F. Plan on at least 30 gal.

What temperature suits both glass catfish and pencilfish?

75–80 °F. Glass catfish need 75–80 °F, pencilfish need 75–82 °F.

What size tank do glass catfish and pencilfish need together?

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