To grow hydroponic lettuce successfully, maintain a water pH of 5.5–6.5 and a TDS of 560–840 ppm (EC 0.8–1.2) while providing 12–16 hours of light and cool temperatures between 15°C and 24°C. This fast-growing crop is ideal for vertical towers and can be harvested in as little as 30 days.
Lettuce Growing Requirements
| Parameter | Optimal Range |
|---|---|
| pH Level | 5.5 – 6.5 |
| TDS (Total Dissolved Solids) | 560 – 840 ppm |
| EC (Electrical Conductivity) | 0.8 – 1.2 mS/cm |
| Temperature | 15°C – 24°C (Day) / 10°C – 18°C (Night) |
| Light Requirements | 12 – 16 Hours (Full Spectrum) |
Recommended Hydroponic Setup
Lettuce thrives in Vertical Hydroponic Towers because its shallow root system benefits from the consistent trickle of oxygenated water. Systems like the 6-Tier Tower Kit allow for high-density planting, maximizing your leafy green yield in small spaces.
Growth Stages & Harvesting
- Germination (Days 1-7): Start seeds in Coco Discs. Keep them moist until the first true leaves appear.
- Transplanting (Week 2): Move seedlings into Net Pots once they are 2 inches tall.
- Vegetative Growth (Weeks 3-5): Ensure consistent nutrient flow using a balanced Nutrient Solution.
- Harvesting (Week 5+): Use the “cut and come again” method by harvesting outer leaves, or harvest the entire head once it reaches desired size.
Common Problems & Maintenance
- Tip Burn: Often caused by poor airflow or calcium deficiency. Ensure your tower is in a well-ventilated area.
- Bolting: If temperatures exceed 27°C, lettuce may turn bitter and produce seeds. Keep the reservoir water cool.
- Yellow Leaves: Check your TDS levels; yellowing often indicates a nutrient deficiency or incorrect pH.
For a complete setup guide, visit our Installation Guide or explore more Vertical Hydroponics Pillars.