Can Bolivian Ram live with Oscar?
These two species are usually compatible in community tanks.
Why Bolivian Ram and Oscar Work
These two species overlap in both temperature (74–81°F overlap) and pH (6.0-7.5 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 + aggressive) is low-conflict. In a 75+ gallon tank with adequate hiding spots, these two can coexist with minimal problems.
Bolivian Ram
Mikrogeophagus altispinosus
| Adult Size: | 3.0" |
| Temperament: | peaceful |
| Min Tank: | 30 gal |
| Temperature: | 74-82°F |
| pH Range: | 6.0-7.5 |
Oscar
Astronotus ocellatus
| Adult Size: | 12.0" |
| Temperament: | aggressive |
| Min Tank: | 75 gal |
| Temperature: | 74-81°F |
| pH Range: | 6.0-7.5 |
Water Parameter Overlap
| Parameter | Bolivian Ram | Oscar | Overlap |
|---|---|---|---|
| Temperature | 74-82°F | 74-81°F | 7°F ✓ |
| pH | 6.0-7.5 | 6.0-7.5 | 1.5 ✓ |
Compatibility Breakdown
Temperament Match: peaceful + aggressive. One aggressive → predation/nipping risk.
⚠️ Size Predation Risk: Bolivian Ram (3.0") vs Oscar (12.0"). A 9.0" 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: 85.0/100 (GOOD ≥80, CAUTION ≥50, RISKY <50).
🔧 Tank Setup Requirements (for Both)
- Minimum tank: 75 gallons — sized for the larger fish in the pair.
- Temperature: keep it between 74°F and 81°F.
- pH: maintain 6.0 – 7.5.
- Hiding spots: essential for Bolivian Ram — 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 75+ gallons:
High-capacity canister filter for oscar tanks
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 Bolivian Ram 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.