{"id":1457,"date":"2022-09-14T08:06:45","date_gmt":"2022-09-14T08:06:45","guid":{"rendered":"https:\/\/ledask.com\/?p=1457"},"modified":"2022-09-29T08:15:48","modified_gmt":"2022-09-29T08:15:48","slug":"ppf-vs-ppfd","status":"publish","type":"post","link":"https:\/\/ledask.com\/ppf-vs-ppfd\/","title":{"rendered":"PPF vs. PPFD: The Best Measurement for Grow Lights"},"content":{"rendered":"\n

LEDs are useful for many things, including grow lights<\/a>. Also, PPFD and PPF determine how much illumination plants will get from your LED lamps. But if you’re a novice in the horticulture world, there’s a high chance you haven’t heard about PPF vs. PPFD measurements. In truth, these metrics can be a bit tricky.<\/p>\n\n\n\n

In this article, you will see a comparison of PPF vs. PPFD metrics to help you know the method that works best for your grow lights.<\/p>\n\n\n

What is PPF & PPFD?<\/h2>\n\n\n
\"Light<\/figure>\n\n\n\n

Light fixture over two plants<\/em><\/p>\n\n\n\n

PPF and PPFD refer to the amount of light a light source generates in a location. PPF is an acronym for Photosynthetic Photon Flux, while PPFD stands for Photosynthetic Photon Flux Density.<\/p>\n\n\n\n

Photons are single light particles that take on various wavelengths.  Also, they work as photosynthetic photons for photosynthesis (specifical photons with 400 nm to 700nm wavelengths<\/a>). However, it’s crucial to understand what photosynthetic photons are before we jump into what these metrics mean.<\/p>\n\n\n\n

But how do you measure the number of photons? That’s the job of PPF and PPFD. The significant difference between the two metrics is that PPF measures the total number of photons a light source releases. And PPFD handles the density of the photons on a specific surface.<\/p>\n\n\n

Understanding PAR (Photosynthetic Active Radiation)<\/h2>\n\n\n
\"Grow<\/figure>\n\n\n\n

Grow light over plants<\/em><\/p>\n\n\n\n

PAR refers to visible light within a 400 nm to 700 nm range.  And on the color spectrum, the range covers all wavelengths from blue to red. So, you can use a PAR meter to calculate how much PAR light a lamp generates.<\/p>\n\n\n

How to Measure PAR<\/h3>\n\n\n

Measuring light can be tricky. And that’s because you have to account for the number of photons a single light emits per second over a specific surface area.<\/p>\n\n\n\n

In addition, you can use moles when referring to the light per day from the sun and micromoles for those coming from lighting fixtures.<\/p>\n\n\n

PPF vs. PPFD: The Differences <\/h2>\n\n\n

Let’s look closely at several factors that help differentiate these metrics.<\/p>\n\n\n

Units of Measure<\/h3>\n\n\n

At first, it seems like most lights produce the same amount of photons. But in reality, fluctuations occur frequently.<\/p>\n\n\n\n

And it doesn’t pose a problem for quality LED grow lights as these upgraded technologies produce more consistent outputs. But, accuracy is necessary for LED grow lights, so measuring is crucial.<\/p>\n\n\n\n

Both metrics have different units of measure for the total number of photons. PPF measures photons in μmol\/s, while PPFD calculates with μmol\/s\/m2<\/sup>. <\/p>\n\n\n\n

Since the values for measuring photons are large, the metrics use micromoles (μmol). Therefore, we can estimate one micromole to be 6 x 1017<\/sup>. Also, these formulas account for the rate of photons per second.<\/p>\n\n\n\n

In short, PPF counts micromoles per second, while PPFD handles micromoles per meter squared.<\/p>\n\n\n\n

Note: PPFD accounts for how many photosynthetic photons land on square meters per second.<\/em><\/p>\n\n\n

Applications<\/h3>\n\n\n

PPFD metrics are ideal if you’re considering distance and location. Although most LED grow lights will show PPFD readings, you should watch out for the following factors before comparing values:<\/p>\n\n\n\n