Light Requirements for Hydroponic Lettuce: LEDs vs Natural Sunlight
Home » Hydroponics » Light Requirements for Hydroponic Lettuce: LEDs vs Natural Sunlight Last Updated: August 07, 2026 | Reviewed for accuracy, clarity, and safety Quick Answer: Managing nutrient concentration via Electrical Conductivity (EC) and Parts Per Million (PPM) goes hand in hand with light management. Daily Light Integral (DLI) measures the total volume of light photons delivered to a square meter of plant canopy over 24 hours. For indoor head lettuce, the sweet spot sits between 14.0 and 16.5 mol/m²/day. If DLI drops below 12.0 mol/m²/day, leaves become thin, leggy, and pale due to carbohydrate starvation. ⏱️ Time: 30 Minutes 💪 Difficulty: Beginner 💰 Est. Cost: $50 – $150…