Can Jack Dempsey Live With Three-Lined Pencilfish?
Jack Dempsey and Three-Lined Pencilfish are NOT compatible tank mates.
Detailed Analysis
Temperature
✓ Compatible
Good temperature overlap at 75–82°F.
pH
✓ Compatible
Good pH overlap at 6.5–7.0.
Size
✗ Not Compatible
Extreme size difference. Jack Dempsey (10") may eat or bully Three-Lined Pencilfish (1.5").
Temperament
✗ Not Compatible
Jack Dempsey (aggressive) is not compatible with Three-Lined Pencilfish (peaceful). Aggression or stress is very likely.
Swim Level
✓ Compatible
Fish occupy different water levels (Jack Dempsey: middle, Three-Lined Pencilfish: top), reducing conflict.
Trait Conflict
✗ Not Compatible
Jack Dempsey is a predator and may eat Three-Lined Pencilfish.
Important Notes
- Three-Lined Pencilfish is a schooling fish and needs at least 6 of its kind.
Tank Requirements
Minimum tank size for this combination: 60 gallons
| Parameter | Jack Dempsey | Three-Lined Pencilfish |
|---|---|---|
| Temperature | 72–86°F | 75–82°F |
| pH | 6.5–7.5 | 5–7 |
| Max Size | 10" | 1.5" |
| Temperament | Aggressive | Peaceful |
| Swim Level | Middle | Top |
| Min Tank | 55 gal | 10 gal |
Check More Combinations
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