Can firemouth cichlids live with black skirt tetras?

Verdict
Yes

Yes. Firemouth cichlids and black skirt tetras make a good pair. Both are fine at 75–80°F. Plan on at least 30 gal.

Firemouth cichlidFiremouth cichlid75–86°F · pH 6.5–8 Black skirt tetraBlack skirt tetra70–80°F · pH 6–7.5

Why it works

Water side by side

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

Size to scale

Firemouth cichlid · 6 inBlack skirt tetra · 2.5 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 cichlidBlack skirt tetra
Temperature75–86 °F70–80 °F
pH6.5–86–7.5
Adult size6.0 in2.5 in
Minimum tank30 gal15 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 black skirt tetras

All black skirt tetra tank mates

Questions

Can firemouth cichlids live with black skirt tetras?

Yes. Firemouth cichlids and black skirt tetras make a good pair. Both are fine at 75–80°F. Plan on at least 30 gal.

What temperature suits both firemouth cichlids and black skirt tetras?

75–80 °F. Firemouth cichlids need 75–86 °F, black skirt tetras need 70–80 °F.

What size tank do firemouth cichlids and black skirt tetras need together?

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