Can Emperor Tetra live with Firemouth Cichlid?
Case-by-case. Watch group sizes, tank size, and feeding zones.
Why Emperor Tetra and Firemouth Cichlid Don't Make an Easy Pair
They can coexist, but you need to manage the setup carefully. The temperament combination (peaceful+semi-aggressive) can work, but you will need to watch them at feeding time for the first week.
Emperor Tetra
Nematobrycon palmeri
| Adult Size: | 2.0" |
| Temperament: | peaceful |
| Min Tank: | 20 gal |
| Temperature: | 73-82°F |
| pH Range: | 5.5-7.0 |
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 |
Water Parameter Overlap
| Parameter | Emperor Tetra | Firemouth Cichlid | Overlap |
|---|---|---|---|
| Temperature | 73-82°F | 75-86°F | 7°F ✓ |
| pH | 5.5-7.0 | 6.5-8.0 | 0.5 ✓ |
Compatibility Breakdown
Temperament Match: peaceful + semi-aggressive. Semi-aggressive → watch territory and feeding.
⚠️ Size Predation Risk: Emperor Tetra (2.0") vs Firemouth Cichlid (6.0"). A 4.0" gap — the larger fish will view the smaller fish as food.
Score: 70.0/100 (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 82°F.
- pH: maintain 6.5 – 7.0.
- Hiding spots: essential for Emperor Tetra — 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
See what else works with these fish:
⚠️ Common Reasons This Pairing Fails in Practice
- Size-based predation: The 4.0" size gap means the larger fish may eat the smaller one once it grows to full size. This is not fixable with more hiding spots.
- Overcrowding: Even compatible species fail in tanks that are too small. Double the species means double the bioload — 25% weekly water changes are the minimum.
- Inadequate acclimation: Adding both species on the same day without quarantine is a common mistake. Always drip-acclimate new arrivals and quarantine for 2–4 weeks.
Tools & Resources
Accuracy note: This tool uses expert rules + FishBase.org data. Individual fish behavior varies — a peaceful individual Emperor Tetra 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.