Can discus live with firemouth cichlids?

Verdict
Yes

Yes, discus and firemouth cichlids can live together. Both are fine at 82–86°F. Plan on at least 55 gal.

DiscusDiscus82–88°F · pH 5.5–7 Firemouth cichlidFiremouth cichlid75–86°F · pH 6.5–8

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 82–86°Discus 82–88°Firemouth cichlid 75–86°
The green band is the temperature range both can live in.
456789Both: 6.5–7Discus 5.5–7Firemouth cichlid 6.5–8
The green band is the pH both tolerate.

Size to scale

Discus · 6 inFiremouth cichlid · 6 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

DiscusFiremouth cichlid
Temperature82–88 °F75–86 °F
pH5.5–76.5–8
Adult size6.0 in6.0 in
Minimum tank55 gal30 gal
TemperamentPeacefulSemi-aggressive
Swims atMiddleBottom
GroupGroups of 5+Alone or in pairs
DietCarnivoreOmnivore

Better tank mates for discus

All discus tank mates

Better tank mates for firemouth cichlids

All firemouth cichlid tank mates

Questions

Can discus live with firemouth cichlids?

Yes, discus and firemouth cichlids can live together. Both are fine at 82–86°F. Plan on at least 55 gal.

What temperature suits both discus and firemouth cichlids?

82–86 °F. Discus need 82–88 °F, firemouth cichlids need 75–86 °F.

What size tank do discus and firemouth cichlids need together?

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