Can Bristlenose Pleco live with Silver Arowana?
These two species are usually compatible in community tanks.
Why Bristlenose Pleco and Silver Arowana Work
These two species overlap in both temperature (75–82°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 250+ gallon tank with adequate hiding spots, these two can coexist with minimal problems.
Bristlenose Pleco
Ancistrus cirrhosus
| Adult Size: | 5.0" |
| Temperament: | peaceful |
| Min Tank: | 30 gal |
| Temperature: | 73-82°F |
| pH Range: | 6.5-7.5 |
Silver Arowana
Osteoglossum bicirrhosum
| Adult Size: | 36.0" |
| Temperament: | semi-aggressive |
| Min Tank: | 250 gal |
| Temperature: | 75-82°F |
| pH Range: | 6.0-7.5 |
Water Parameter Overlap
| Parameter | Bristlenose Pleco | Silver Arowana | Overlap |
|---|---|---|---|
| Temperature | 73-82°F | 75-82°F | 7°F ✓ |
| pH | 6.5-7.5 | 6.0-7.5 | 1.0 ✓ |
Compatibility Breakdown
Temperament Match: peaceful + semi-aggressive. Semi-aggressive → watch territory and feeding.
⚠️ Size Predation Risk: Bristlenose Pleco (5.0") vs Silver Arowana (36.0"). A 31.0" gap — the larger fish will view the smaller fish as food.
⚠️ Diet Conflict: A carnivore sharing water with a fish small enough to fit in its mouth is a waiting game. Feed generously, but the risk is structural — not something you can manage meal by meal.
Score: 80.0/100 (GOOD ≥80, CAUTION ≥50, RISKY <50).
🔧 Tank Setup Requirements (for Both)
- Minimum tank: 250 gallons — sized for the larger fish in the pair.
- Temperature: keep it between 75°F and 82°F.
- pH: maintain 6.5 – 7.5.
- Hiding spots: essential for Bristlenose Pleco — 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 250+ gallons:
Floating food sticks for large carnivorous surface 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 Bristlenose Pleco 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.