Can platies live with firemouth cichlids?

Verdict
Yes

Yes, platies and firemouth cichlids can live together. Both are fine at 75–80°F. Plan on at least 30 gal.

PlatyPlaty70–80°F · pH 7–8.2 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: 75–80°Platy 70–80°Firemouth cichlid 75–86°
The green band is the temperature range both can live in.
456789Both: 7–8Platy 7–8.2Firemouth cichlid 6.5–8
The green band is the pH both tolerate.

Size to scale

Platy · 2.5 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

PlatyFiremouth cichlid
Temperature70–80 °F75–86 °F
pH7–8.26.5–8
Adult size2.5 in6.0 in
Minimum tank10 gal30 gal
TemperamentPeacefulSemi-aggressive
Swims atMiddleBottom
GroupGroups of 3+Alone or in pairs
DietOmnivoreOmnivore

Better tank mates for platies

All platy tank mates

Better tank mates for firemouth cichlids

All firemouth cichlid tank mates

Questions

Can platies live with firemouth cichlids?

Yes, platies and firemouth cichlids can live together. Both are fine at 75–80°F. Plan on at least 30 gal.

What temperature suits both platies and firemouth cichlids?

75–80 °F. Platies need 70–80 °F, firemouth cichlids need 75–86 °F.

What size tank do platies and firemouth cichlids need together?

At least 30 gal, set by the firemouth cichlid. Add space for each extra fish.