In grow lighting, PPF (Photosynthetic Photon Flux) is a key measurement used to evaluate how much light a grow light outputs. PPF is measured in micromoles per second (µmol/s) and refers to the total amount of photosynthetically active radiation (PAR) emitted by a light source every second.
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PAR covers the range of light wavelengths from 400 to 700 nanometers, which are essential for photosynthesis—the process by which plants convert light into the energy they need to grow.
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Unlike PPFD (Photosynthetic Photon Flux Density), which measures the amount of light that actually reaches a specific area, PPF simply indicates how much light a fixture produces overall, regardless of where it lands.
This makes PPF particularly useful for comparing the output of different light fixtures. For instance, a light with a higher PPF produces more photons per second, which generally means more potential energy available for plant growth.