Can Silver Dollar live with Swordtail?
Case-by-case. Watch group sizes, tank size, and feeding zones.
Why Silver Dollar 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.
Silver Dollar
Metynnis argenteus
| Adult Size: | 6.0" |
| Temperament: | peaceful |
| Min Tank: | 55 gal |
| Temperature: | 75-82°F |
| pH Range: | 6.0-7.5 |
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 | Silver Dollar | Swordtail | Overlap |
|---|---|---|---|
| Temperature | 75-82°F | 72-78°F | 3°F ✓ |
| pH | 6.0-7.5 | 7.0-8.0 | 0.5 ✓ |
Compatibility Breakdown
Temperament Match: peaceful + 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: 55 gallons — sized for the larger fish in the pair.
- Temperature: keep it between 75°F and 78°F.
- pH: maintain 7.0 – 7.5.
- Hiding spots: essential for Silver Dollar — 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 55+ gallons:
Herbivore sinking rounds for plant-eating fish
Explore Related Checks
See what else works with these fish:
Accuracy note: This tool uses expert rules + FishBase.org data. Individual fish behavior varies — a peaceful individual Silver Dollar 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.