Can Firemouth Cichlid live with Swordtail?
Case-by-case. Watch group sizes, tank size, and feeding zones.
Why Firemouth Cichlid and Swordtail Don't Make an Easy Pair
They can coexist, but you need to manage the setup carefully. The temperature margin is tight — only 3°F of safe overlap, which leaves little room for thermostat drift.
Firemouth Cichlid
Thorichthys meeki
| Adult Size: | 6.0" |
| Temperament: | semi-aggressive |
| Min Tank: | 30 gal |
| Temperature: | 75-86°F |
| pH Range: | 6.5-8.0 |
Swordtail
Xiphophorus helleri
| Adult Size: | 5.0" |
| Temperament: | semi-aggressive |
| Min Tank: | 20 gal |
| Temperature: | 72-78°F |
| pH Range: | 7.0-8.0 |
Water Parameter Overlap
| Parameter | Firemouth Cichlid | Swordtail | Overlap |
|---|---|---|---|
| Temperature | 75-86°F | 72-78°F | 3°F ✓ |
| pH | 6.5-8.0 | 7.0-8.0 | 1.0 ✓ |
Compatibility Breakdown
Temperament Match: semi-aggressive + semi-aggressive. Semi-aggressive → watch territory and feeding.
Score: 60.0/100 (GOOD ≥80, CAUTION ≥50, RISKY <50).
🔧 Tank Setup Requirements (for Both)
- Minimum tank: 30 gallons — sized for the larger fish in the pair.
- Temperature: keep it between 75°F and 78°F.
- pH: maintain 7.0 – 8.0.
- Hiding spots: essential for Firemouth Cichlid — caves, plants, or driftwood to retreat when feeling stressed.
- Water changes: 25% weekly minimum. Two species mean double the bioload.
🔧 Tank Stocking Calculator
Enter tank size to calculate safe stocking levels:
Recommended Equipment
Based on tank size 30+ gallons:
Floating pellet for medium cichlids
Explore Related Checks
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Accuracy note: This tool uses expert rules + FishBase.org data. Individual fish behavior varies — a semi-aggressive individual Firemouth Cichlid may act differently from its species average. Always observe, quarantine new arrivals for 2-4 weeks, and avoid overcrowding. If a pairing says CAUTION, start with a smaller group and a lid.