Can Common Plecostomus live with Red Tail Black Shark?
These two species are usually compatible in community tanks.
Why Common Plecostomus and Red Tail Black Shark Work
These two species overlap in both temperature (72–80°F overlap) and pH (6.5-7.5 overlap range). Their temperature tolerances are close enough, and neither fish pushes the pH so far outside the other's comfort zone that it creates chronic stress. The temperament match (peaceful + semi-aggressive) is low-conflict. In a 55+ gallon tank with adequate hiding spots, these two can coexist with minimal problems.
Common Plecostomus
Hypostomus plecostomus
| Adult Size: | 15.0" |
| Temperament: | peaceful |
| Min Tank: | 55 gal |
| Temperature: | 72-86°F |
| pH Range: | 6.5-7.8 |
Red Tail Black Shark
Epalzeorhynchos bicolor
| Adult Size: | 5.0" |
| Temperament: | semi-aggressive |
| Min Tank: | 30 gal |
| Temperature: | 72-80°F |
| pH Range: | 6.5-7.5 |
Water Parameter Overlap
| Parameter | Common Plecostomus | Red Tail Black Shark | Overlap |
|---|---|---|---|
| Temperature | 72-86°F | 72-80°F | 8°F ✓ |
| pH | 6.5-7.8 | 6.5-7.5 | 1.0 ✓ |
Compatibility Breakdown
Temperament Match: peaceful + semi-aggressive. Semi-aggressive → watch territory and feeding.
⚠️ Size Predation Risk: Common Plecostomus (15.0") vs Red Tail Black Shark (5.0"). A 10.0" gap — the larger fish will view the smaller fish as food.
Score: 90.0/100 (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 72°F and 80°F.
- pH: maintain 6.5 – 7.5.
- Hiding spots: essential for Common Plecostomus — 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:
Sinking wafers for plecos and bottom feeders
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 Common Plecostomus 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.