LED Lighting Deep Dive
Your light is the single most important factor in your cannabis grow. This guide covers everything you need to know to choose the right LED for your space and budget.
Why LED Has Won
Modern LED grow lights have replaced HPS (high pressure sodium) as the standard for home growers. LEDs run cooler (less heat stress, lower electricity bills), last longer (50,000+ hours vs 10,000 for HPS), and modern full-spectrum LEDs match or exceed HPS yields while using 40–50% less electricity.
Understanding PPFD and Coverage
PPFD (Photosynthetic Photon Flux Density) measures how much light actually reaches your plants in micromoles per square metre per second (µmol/m²/s). Seedlings need 200–400 µmol/m²/s. Veg stage needs 400–600. Flower stage needs 600–900. Most LED manufacturers provide PPFD maps at different hanging heights — use these to choose the right light for your space.
Full Spectrum vs Blurple
Avoid purple (blurple) LEDs that combine only red and blue diodes. They were the first generation of LED grow lights and produce inferior results. Modern full-spectrum quantum board LEDs (using Samsung LM301B/H or Osram diodes) produce white light that covers the full spectrum plants need. They cost more upfront but produce significantly better results.
Wattage Guidelines
As a rule of thumb for quality LED boards: 25–40W true power per square foot of canopy (270–430W per m²). A 60x60cm tent needs a genuine 100–150W LED. An 80x80cm tent needs 200–250W. Do not trust "equivalent wattage" claims — only true draw wattage from the wall matters.
Top LED Brands for Home Growers
Mid-budget (€100–250): Spider Farmer SF series, Mars Hydro TS/FC series, Viparspectra KS series. These all use quality Samsung diodes and are genuine value. Higher-end (€300+): HLG (Horticulture Lighting Group) quantum boards are the gold standard. Chinese budget brands from Amazon with inflated wattage claims should be avoided.
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Quick Tips
- Dim your light to 50% for seedlings and gradually increase as plants mature.
- Get a PAR meter app on your phone (free) to measure your actual PPFD — not perfect but better than guessing.
- Clean dust off your LED lenses every few weeks — dust reduces light output significantly over time.