Can firemouth cichlids live with swordtails?

Verdict
Yes

Yes. Firemouth cichlids and swordtails 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 SwordtailSwordtail72–79°F · pH 7–8.3

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–79°Firemouth cichlid 75–86°Swordtail 72–79°
The green band is the temperature range both can live in.
456789Both: 7–8Firemouth cichlid 6.5–8Swordtail 7–8.3
The green band is the pH both tolerate.

Size to scale

Firemouth cichlid · 6 inSwordtail · 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 cichlidSwordtail
Temperature75–86 °F72–79 °F
pH6.5–87–8.3
Adult size6.0 in5.0 in
Minimum tank30 gal30 gal
TemperamentSemi-aggressiveSemi-aggressive
Swims atBottomMiddle
GroupAlone or in pairsGroups of 3+
DietOmnivoreOmnivore

Better tank mates for firemouth cichlids

All firemouth cichlid tank mates

Better tank mates for swordtails

All swordtail tank mates

Questions

Can firemouth cichlids live with swordtails?

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

What temperature suits both firemouth cichlids and swordtails?

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

What size tank do firemouth cichlids and swordtails need together?

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