Can Electric Yellow Lab live with Jack Dempsey?
High risk due to water mismatch, aggression, or predation.
Why Electric Yellow Lab and Jack Dempsey Don't Make an Easy Pair
The size gap is 6.0" — Electric Yellow Lab (4.0") and Jack Dempsey (10.0"). A fish that fits in another fish's mouth will eventually end up there.
Electric Yellow Lab
Labidochromis caeruleus
| Adult Size: | 4.0" |
| Temperament: | semi-aggressive |
| Min Tank: | 30 gal |
| Temperature: | 75-82°F |
| pH Range: | 7.8-8.6 |
Jack Dempsey
Rocio octofasciata
| Adult Size: | 10.0" |
| Temperament: | aggressive |
| Min Tank: | 55 gal |
| Temperature: | 72-82°F |
| pH Range: | 6.5-8.0 |
Water Parameter Overlap
| Parameter | Electric Yellow Lab | Jack Dempsey | Overlap |
|---|---|---|---|
| Temperature | 75-82°F | 72-82°F | 7°F ✓ |
| pH | 7.8-8.6 | 6.5-8.0 | 0.2 ✓ |
Compatibility Breakdown
Temperament Match: semi-aggressive + aggressive. One aggressive → predation/nipping risk.
⚠️ Size Predation Risk: Electric Yellow Lab (4.0") vs Jack Dempsey (10.0"). A 6.0" 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: 49.0/100 (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 75°F and 82°F.
- pH: maintain 7.8 – 8.0.
- Hiding spots: essential for Electric Yellow Lab — 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:
Floating pellet for medium to large cichlids
Explore Related Checks
See what else works with these fish:
⚠️ Common Reasons This Pairing Fails in Practice
- Size-based predation: The 6.0" size gap means the larger fish may eat the smaller one once it grows to full size. This is not fixable with more hiding spots.
- Diet-driven aggression: A carnivore sharing a tank with bite-sized tank mates creates structural risk — no amount of generous feeding eliminates the instinct to hunt.
- Aggression risk: An aggressive species will dominate feeding zones and chase the other fish into hiding. Chronic stress weakens the immune system and shortens lifespan.
- Overcrowding: Even compatible species fail in tanks that are too small. Double the species means double the bioload — 25% weekly water changes are the minimum.
- Inadequate acclimation: Adding both species on the same day without quarantine is a common mistake. Always drip-acclimate new arrivals and quarantine for 2–4 weeks.
- Mismatched feeding: Electric Yellow Lab is a omnivore while Jack Dempsey is a carnivore. Use targeted feeding zones and sinking vs. floating food to ensure both get proper nutrition.
Tools & Resources
Accuracy note: This tool uses expert rules + FishBase.org data. Individual fish behavior varies — a semi-aggressive individual Electric Yellow Lab 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.