Can Flowerhorn live with Oscar?
Case-by-case. Watch group sizes, tank size, and feeding zones.
Why Flowerhorn and Oscar 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.
Flowerhorn
Amphilophus hybrid
| Adult Size: | 12.0" |
| Temperament: | aggressive |
| Min Tank: | 75 gal |
| Temperature: | 78-86°F |
| pH Range: | 6.5-8.0 |
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 | Flowerhorn | Oscar | Overlap |
|---|---|---|---|
| Temperature | 78-86°F | 74-81°F | 3°F ✓ |
| pH | 6.5-8.0 | 6.0-7.5 | 1.0 ✓ |
Compatibility Breakdown
Temperament Match: aggressive + aggressive. One aggressive → predation/nipping risk.
Score: 50.0/100 (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 78°F and 81°F.
- pH: maintain 6.5 – 7.5.
- Hiding spots: essential for Oscar — 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:
Large pellet food for big cichlids like flowerhorn
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 aggressive individual Flowerhorn 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.