Can firemouth cichlids live with serpae tetras?

Verdict
Yes

Yes. Firemouth cichlids and serpae tetras make a good pair. Both are fine at 75–79°F. Plan on at least 30 gal.

Firemouth cichlidFiremouth cichlid75–86°F · pH 6.5–8 Serpae tetraSerpae tetra72–79°F · pH 6–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–79°Firemouth cichlid 75–86°Serpae tetra 72–79°
The green band is the temperature range both can live in.
456789Both: 6.5–7.5Firemouth cichlid 6.5–8Serpae tetra 6–7.5
The green band is the pH both tolerate.

Size to scale

Firemouth cichlid · 6 inSerpae tetra · 1.75 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 cichlidSerpae tetra
Temperature75–86 °F72–79 °F
pH6.5–86–7.5
Adult size6.0 in1.75 in
Minimum tank30 gal20 gal
TemperamentSemi-aggressiveSemi-aggressive
Swims atBottomMiddle
GroupAlone or in pairsGroups of 6+
DietOmnivoreOmnivore

Better tank mates for firemouth cichlids

All firemouth cichlid tank mates

Better tank mates for serpae tetras

All serpae tetra tank mates

Questions

Can firemouth cichlids live with serpae tetras?

Yes. Firemouth cichlids and serpae tetras make a good pair. Both are fine at 75–79°F. Plan on at least 30 gal.

What temperature suits both firemouth cichlids and serpae tetras?

75–79 °F. Firemouth cichlids need 75–86 °F, serpae tetras need 72–79 °F.

What size tank do firemouth cichlids and serpae tetras need together?

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