Can firemouth cichlids live with peacock cichlids?

Verdict
Yes

Yes. Firemouth cichlids and peacock cichlids get along in the same tank. Both are fine at 76–82°F. Plan on at least 55 gal.

Firemouth cichlidFiremouth cichlid75–86°F · pH 6.5–8 Peacock cichlidPeacock cichlid76–82°F · pH 7.8–8.6

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 76–82°Firemouth cichlid 75–86°Peacock cichlid 76–82°
The green band is the temperature range both can live in.
456789Both: 7.8–8Firemouth cichlid 6.5–8Peacock cichlid 7.8–8.6
The green band is the pH both tolerate.

Size to scale

Firemouth cichlid · 6 inPeacock 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

Firemouth cichlidPeacock cichlid
Temperature75–86 °F76–82 °F
pH6.5–87.8–8.6
Adult size6.0 in6.0 in
Minimum tank30 gal55 gal
TemperamentSemi-aggressiveSemi-aggressive
Swims atBottomMiddle
GroupAlone or in pairsGroups of 4+
DietOmnivoreCarnivore

Better tank mates for firemouth cichlids

All firemouth cichlid tank mates

Better tank mates for peacock cichlids

All peacock cichlid tank mates

Questions

Can firemouth cichlids live with peacock cichlids?

Yes. Firemouth cichlids and peacock cichlids get along in the same tank. Both are fine at 76–82°F. Plan on at least 55 gal.

What temperature suits both firemouth cichlids and peacock cichlids?

76–82 °F. Firemouth cichlids need 75–86 °F, peacock cichlids need 76–82 °F.

What size tank do firemouth cichlids and peacock cichlids need together?

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