LED Grow Light Buying Guide 2026: PPFD, Spectrum, and the Spec Sheets That Lie
How to read a grow-light datasheet, why 'equivalent wattage' is meaningless, and three lights we'd actually buy this year.
Iris Okafor·April 30, 2026·11 min read
The only numbers that matter
Photosynthetic Photon Flux Density (PPFD), measured in µmol/m²/s, tells you how much usable light reaches the canopy. Photon efficacy (µmol/J) tells you how efficiently watts become photons. Everything else — 'lumens', 'equivalent HPS', LED count — is marketing noise.
Spectrum: full vs targeted
For a mixed home grow, full-spectrum white (3000K–4000K) plus a touch of 660nm red is the safest choice. Pure blue/red 'blurple' panels work but make plant inspection miserable.
What we'd buy
For a 60×60cm tent: a 120W Samsung LM301H-based bar light. For a 1.2×1.2m tent: a 480W quantum board. For a kitchen shelf: a 30W clip-on. We track our lab tests in our gear database.