The Sweet Spot of Light: Getting Your HPS and LED Intensity Just Right
Understanding Photosynthetic Photon Flux Density (PPFD)
You may have heard the term "PPFD" being thrown around in gardening circles, especially when discussing indoor growing. But what is it, and why should you care?
PPFD stands for Photosynthetic Photon Flux Density, and it is a way of measuring the amount of light that plants can use for photosynthesis. Think of it like this: PPFD is the number of photons hitting a specific area of your plant's leaves at any given second.
Why does PPFD matter?
The more light your plant can use, the better it will grow, and the more likely it is to produce a large, healthy harvest. But there is a sweet spot. Too much light can cause stress and damage your plants. Think of it like a sunburnt plant. Too little light, and your plant won't be able to reach its full potential.
How is PPFD measured?
PPFD is measured in micromoles per square meter per second (μmol⋅m−2⋅s−1). Don't let the technical jargon scare you! All you need to know is that this is the standard measurement for grow lights, and it's what you should look for when choosing a grow light.
Recommended PPFD levels for your plants
Here is a table with the recommended PPFD for each stage of the cannabis plant's life cycle:
Plant Stage Recommended PPFD (without Co2)
Germination 100-300
Seedling 200-400
Vegetative 400-600
Flowering 600-1000
How to adjust PPFD
The easiest way to adjust the PPFD is by changing the distance between your grow light and your plants. The closer the light, the higher the PPFD. But be careful not to get too close, or you could burn your plants!
You can also adjust the intensity of your grow light. Some grow lights have a dimmer switch that allows you to control the brightness. This is a great way to fine-tune your PPFD and ensure that your plants are getting the perfect amount of light.
Conclusion
PPFD is an important factor to consider when growing cannabis indoors. By understanding how to measure and adjust PPFD, you can give your plants the best possible chance of success
Heres a link to purchase a top range light meter: