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.
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.
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.