How Do I Add More Micromoles To Grow Tent

Demystifying Light Levels for Cannabis Grows

Disclaimer: Nothing on the PL Light Systems website or digital journal, including but not limited to textual, visual, or editorial material, or external links on the website and digital journal, will be construed as encouraging any unlawful or criminal acts in your jurisdiction. As more and more investors, opportunists, and cultivators join the green rush that is now engulfing the cannabis market, there is also a significant influx of people who are learning as they go about their business. Lighting is a significant investment in this industry because a large percentage of growers still prefer the better climate control and security of growing indoors, and even those who choose to grow in a greenhouse are discovering that no matter where they are in the world, they still require additional lighting to produce a high-quality product all year!

When it comes to real, measurable data, this segment of the horticulture lighting business is still in its infancy.

That is the light level or the amount of light that is required for a crop.

As a result, what is suitable for you may not be the best decision for others.

Unpacking supplemental lighting metrics

As “The Lighting Knowledge Company” PL Light aspires to be your source of knowledge to help weed through the onslaught of material you may discover on line and especially while investigating lighting for cannabis. Let’s start with a discussion of the proper unit of measurement for lighting a crop. This would be a bemoles situation. Lux and foot candles are the most often used units of measurement for light in the United States; however, these units are an instantaneous measurement of the intensity of light that is visible to the human eye — which is typically between 500 and 600 nanometers.

The quantity of real photons that fall on a square meter throughout the course of a certain length of time is the mole measurement (photo period).

Understanding Micromoles

The word micromoles (mol) is familiar to most growers, and they may even have a specific figure in mind for how many micromoles they intend to cultivate. For indoor crops, this value is often between 850 and 1000. Now, let’s take a moment to talk about how this number came to be. To begin, what exactly is a micromole? A micromole is just one millionth of a mole, which is the smallest unit of measurement (micro). Using a micromole measurement of the PAR for your crop, you may determine the number of photons given per square meter per second in your crop.

It is exactly this quantity — the total number of moles – that is critical to the success of your crop.

So why does everyone refer to micromoles? Using a par sensor, we can measure your light level since a micromole is a per second, immediate image of your light level at that precise point in time. This explains why there are so many requests for 900 micromoles of THC on a marijuana crop.

Let’s break this down to understand the importance of this micromole number.

Any fruit-bearing crop – tomatoes, peppers, and so forth – will require between 20 and 40 moles each day in order to produce fruit. For the sake of illustration, consider the tomato. A farmer who wants to obtain excellent development from his crop may wish to set our light levels at roughly 30-32 moles each day if he wants to achieve superior growth from his crop. The production curve of a crop in response to the number of moles provided each day dramatically increases between 20 and 30 moles, begins to truly level out between 30 and 40 moles, and after 40 moles, the crop begins to reach a point of diminishing returns.

Assuming he intends to use lights for 16 hours a day, we can perform the following calculations to get the light levels in micromoles we wish to target:

32 moles/ 16 hr photoperiod / 60 minutes / 60 seconds = 0.000556 moles(This gives us the amount of moles delivered per second per square meter)

In this case, cannabis has a substantially higher occurrence rate than in the previous example because of the crop’s photoperiod need. In order to begin flowering the cannabis bud, we must allow for 12 hours of darkness every night. Furthermore, cannabis currently has a bigger profit margin than most other crops, so even while the production curve in response to the quantity of light starts to level out around the 30 – 40 mole region, most producers will stretch it out as much as they can to maximize their profits.

900 µmolsx 60 seconds x 60 minutes x 12 hours = 38,880,000 µmols(This gives us the amount of µmoles delivered in a 12 hr period)

Growers that use high-pressure sodium (HPS) lighting will not be effective in all situations; some may struggle with the heat if using HPS, while others will find the sheer amount of the power bill to be a hindrance in their efforts. Many gardeners achieve excellent results when they generate 30 moles in a 12-hour period (about 700 micromoles).

Greenhouse Application

In the case of a greenhouse grow, what does this mean exactly? When it comes to my greenhouse, should I aim for 900 mols?” This is a question we are asked rather frequently! You are already receiving a sufficient amount of light from the sun in your greenhouse, but depending on where your house is located in the world and what time of year it is, you could receive as little as 5 moles per day (as is the case in northern climates during winter) or as much light as you require (as is the case in tropical climates during summer) (As is Arizona in the summer).

If our tomato producer is growing in a greenhouse in central Oregon and wants to keep his crop producing at a rate of 32 moles per day year-round, we must consult a Daily Light Integral (DLI) map for the location in question.

We propose that he augment this natural light with 22 moles of illumination each 16-hour photoperiod to attain his 32 mole aim while planning his light levels for his grow.

A total of 382 mols of additional illumination is required.

Again, we will budget for the 10 moles of natural light he will receive and set our lighting to a target of 22 moles to compensate: 22 moles/12 hours/60 minutes/60 seconds x 1,000,000 = 509 mols × 1,000,000 = 509 mols A total of 509 mols of additional illumination is required.

Light Levels Conclusion

As you can see, the micromoles required for the crop are directly proportional to the amount of photoperiod your day receives. Although cannabis requires more illumination than other fruit-bearing crops, the fact is that you only have 12 hours to amass the necessary quantity of light for cannabis. Tomatoes, cucumbers, and roses are examples of crops that are called “day-neutral” plants. In other words, they do not commence blooming in response to changes in photoperiod, and instead may initiate flowering exclusively in response to changes in plant maturity.

Writen by –Eric Moody, Sales Manager for the Americas, who has extensive experience in collaborating with producers at all phases of the growing process.

Make contact with Eric.

Grow Hack: Increase Light Intensity By 60% With This Simple Trick

Indoor grow books constantly stress the need of employing reflectors to make the most of every beam of light that your growlamp emits, but most novice growers are unaware of just how important this is in actual practice. HIGH TIMES has calculated roughly how much light you can conserve by strategically hanging reflectors, based on a few simple measurements and mathematical estimations. Each day, cannabis consumes an enormous amount of light, making it one of the most crucial variables limiting output.

  1. Good reflector placement in your garden may boost light intensity in the canopy by up to 60% without the need to add extra electricity-guzzling, heat-generating bulbs to your landscape.
  2. A photosynthesis photon flux (PPF) is defined as the total of all photosynthetically active photons with wavelengths ranging from 400 nanometers (blue) to 700 nanometers (red), which roughly corresponds to the spectrum of visible light that humans can perceive.
  3. It is measured in micromoles per square meter per second (mol/s/m2), and it is referred to as photosynthetic photon flux density, or PPFD, in the field of photosynthesis.
  4. The Plant Photon Flux Density (PPFD) is the unit of measurement for plant-usable light that covers the canopy of your garden.
  5. For example, orchids require just 8 moles/day/m2 of sunlight for high-quality development, but tomatoes require up to 30 moles/day/m2 of sunlight for high-quality growth.
  6. This book contains DLI maps of the United States, and this publication has a graphic illustrating the DLI needs of many common greenhouse plants.
  7. If we did, it would be broadcast from the summits of mountain peaks from Malibu to Morocco.

According to all appearances, it requires around 25 moles/day/m2 to produce a satisfactory crop, with more light being preferred.

By multiplying this amount by 0.0036, you can get the PPFD that your lights must deliver: 385 mol/s/m 2.

We put it to the test with a spectroradiometer built just for HIGH TIMES.

Placing just two reflectors on either side of the cool-tube (such that the light projected itself on the floor at a 120° angle) resulted in an increase of 59 percent in the peak photon flux density (PPFD).

The light from your growlamps should be completely concentrated on the plants; if any portion of it spills over the floor or the walls, this implies that it is not reaching the plants, and they will not receive the daily dose of light they require to grow productively.

As things stand, the plants growing under a 400 W high-pressure sodium light will only receive a DLI of around 9.8 moles/day/m2.

Simply wrapping the walls of the growroom with aluminum foil will not solve this problem; the beams must reflect directly onto the canopy in order to be effective.

Investing in a legal reflective surface will ensure that you achieve the 90-95 percent reflectivity that you desire.

Don’t allow your yields suffer as a result of inefficient lighting; instead, make the most of your lights and your little garden will be more prolific than you could have anticipated. Image courtesy of VortexFarmacy

Grow Light Uniformity – An Important Factor Of Grow Room Lighting

You’re undoubtedly aware that plants require light to survive and thrive, but have you given any attention to the uniformity of grow light and other lighting considerations? While any light is preferable than no light, there’s no need to settle for anything less than flawless in terms of illumination. The elements to consider while improving your lighting system include the following. Light output, light energy efficiency, and light uniformity all have an influence on the performance of your grow as well as the expense of your energy usage and consumption.

It’s a win-win situation.

Figuring Out Your Light Output

If you’re looking for grow lights, it’s crucial to consider the amount of light they provide. There are several metrics and acronyms associated with grow lights, and it may be difficult to keep track of them all. Take a look at some of the phrases and measures that are important to understand.

Important Terms

The range of light that plants utilise for photosynthesis is referred to as photosynthetic active radiation (PAR). Light with a wavelength in the range of 400-700 nanometers is included in this category. PAR is not a measurement, but rather a technique of describing a spectrum of light in terms of intensity. The quantity of photon flux (PPF) generated by the bulb and ballast is measured using the photosynthetic photon flux (PPF) equation. The PPF is measured in micromoles per second (mo/s), which is a unit of measurement.

  • In addition, it does not entail light reaching a specific region, but rather light emanating from a light source.
  • Micromoles per square meter per second (mol/m2/s) is the unit of measurement for this concentration.
  • Instead of measuring the PPFD directly beneath your light and assuming the same level of illumination reaches your plants, use a light meter.
  • It’s crucial to remember that higher wattage does not automatically equate to better light output or intensity.

What Matters?

Because manufacturers frequently provide a plethora of information on lighting fixtures, it can be difficult to determine what is most important. Should you be concerned with watts? PPF? PPFD? Is it all of it? Take a peek at the PPF first. This value roughly correlates to the brightness of the light source. To put it another way, the greater the PPF, the higher the output of the light bulb. The reflector, on the other hand, is not taken into consideration in this calculation. A significant amount of this light may be lost to the surrounding region or absorbed by the reflector and converted to heat.

  1. Take, for example, the DimLux 1000 Watt light as an illustration.
  2. High pressure sodium (HPS) bulbs have a PPF of 2150 mol/s at 1000 watts, making them the most powerful bulbs available on the market today.
  3. It consumes 1200 watts while operating at this level.
  4. This assists growers in conserving energy and lowering heat production.
  5. When we take a look at the DimLux 1000, we can see that it includes the Alpha Optics 98 reflector as standard equipment.

As a result, rather than being absorbed by the reflector, the great majority (98 percent) of the light generated makes its way to the canopy instead. Remember that this % is based on a clean reflector, so be sure to clean and maintain your reflector on a regular basis.

Increasing Energy Efficiency

The energy efficiency of a lamp is critical to the bottom line of your business. As a result, it is critical to consider both the energy consumption and the output of a light source. Let’s have a look at the DimLux 1000 Watt light once again. It consumes 1000W while it is producing 2150 mol/s of PAR and producing 2150 mol/s of PAR. By dividing the PPF by the consumption, we may determine that this light emits 2.15 mol/s/W of energy. The greater the value of this parameter, the more efficient a light is.

  • When compared to a light that has the same PPF but only consumes 1000 W to create the same output, this light is less efficient.
  • When a light fixture holds on to heat, the region around the bulb becomes hot to the touch.
  • Some types of lighting generate far more heat than others.
  • As a result, LED lights are often associated with decreased cooling costs.
  • Because cooling expenses can quickly build up, it’s a good idea to look into alternative heat-reduction solutions.
  • Ventilation aids in the removal of heat and the maintenance of an optimal light temperature for bulb efficiency.
  • Additionally, this reflector is equipped with a socket that may be used by growers to remove hot air.
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The Importance of Light Uniformity

While gardeners frequently consider issues such as illumination quality, quantity, and efficiency, they may neglect the importance of uniformity in grow light distribution. However, this is not the case! Light homogeneity is equally as crucial as other lighting elements when it comes to lighting design. As you may have imagined, light uniformity is the degree to which light is distributed uniformly throughout a particular region. It is recommended that you aim for 90 percent consistency when establishing ideal lighting for a grow room.

  1. For even growth to occur, it is necessary to maintain consistency.
  2. This results in uneven development, which might result in some plants shading out other plants as a result.
  3. Plants that receive more light will dry out more quickly than those that receive less light.
  4. However, this is also the point at which some ambiguity arises.
  5. There are several reflectors available that may produce consistent light while also reducing the strength of the HID grow light, making it less efficient in penetrating into the second and third tiers of the canopy!

You can boost flower production far into the canopy by using a combination of industry-leading ballasts, lights, and reflectors. This will increase your yields while also pushing the plant to express its full genetic potential.

Factors Impacting Light Uniformity

The majority of lights emit light with varying intensities. Example: The intensity of the light directly beneath the lamp will be larger than the intensity of the light at the far end of its range. Consequently, if you have many lights in a grow room, you must determine the right distance between them in order to achieve optimal light homogeneity. Light homogeneity is influenced by a variety of things. These factors include the quantity of lights you use, the type of lighting you use, the reflectors you use, the distance between your lights, and the height at which your lights are suspended from the ceiling.

Because there are so many variables to consider, there is no one-size-fits-all solution for achieving the best possible light homogeneity.

Having a thorough understanding of the specifications of your lights, they can assist you in designing a system that maximizes light uniformity while also include additional features.

The Global Garden team will respond to you with a custom DimLux lighting scheme created particularly for your garden.

Figuring Out Grow Light Hanging Height

When it comes to hanging grow lights, the objective is to maximize three factors: light intensity, heat, and coverage of the light. When hanging lights, it’s crucial to think about the uniformity of the grow light as well. You want to ensure that every plant in your grow room receives the most amount of light possible. Hanging heights for grow rooms do not come in a single size that suits everybody. The most appropriate hanging height is determined by a variety of factors.

Reflector footprint

Reflectors have an influence on the footprint of a light, or the amount of space it covers. The area covered by a light grows in proportion to the breadth of the reflector. The area illuminated by a light grows in proportion to the height of the light source. As a result, selecting narrower reflectors for high hanging heights and larger reflectors for low hanging heights is frequently the most logical decision. With its adjustable width and thin shape, the Alpha Optics Reflector may be used in either a wide or a narrow configuration.

Number of lights

The bigger the number of lights, the greater the area that may be illuminated. The lower you hang a light, the smaller the area it illuminates. This is true for each light. In general, if you are attempting to illuminate a big area with a single light, you will need to hang this light higher than if you are using two lights to do this.

When employing more than one light, it is critical to evenly distribute the lights across the room so that all regions receive the same amount of light.

Tent size and shape

The number of lights you can hang in your tent or grow room is determined by the size and design of your tent or grow room, as well as the height at which you may hang them. Obviously, as you are aware, you are not permitted to put your lights any higher than the top of your growing area! Remember to take into account how barriers affect light as well. It is possible that light will be lost through the walls if they are not reflecting.

Plants growing

It’s critical to keep track of the size and stage of development of the plants you’re nurturing. When plants are in the vegetative stage, lights should be placed further away from them than when plants are in the blooming stage, even if the lights are the same intensity as when the plants are in the flowering stage. Overall, plants that are dormant require slightly less light than plants that are actively growing.

Type of light

Different types of lights have variable levels of intensity as well as different levels of heat production. Make certain that your lights are not set too low so that they can burn your flowers or plants.

Too High or Too Low?

Now that we understand the parameters that influence grow light hanging height, let’s have a look at what occurs when you hang grow lights at excessively high or low heights. If you place your lights at an inappropriate height, you will encounter a variety of difficulties.

  • The footprint is too large, and light is lost through the walls. Because the amount of light reaching your plants is insufficient, Your plants are not receiving enough heat

Similarly, if you hang your lights too low, you will encounter difficulties.

  • The footprint is too small, and not all plants receive sufficient light. Because of the great intensity of light hitting your plants, they are suffering. The temperature in the region around your plants is very high

Lights for Your System

As you’ve seen in the preceding section, there are a variety of considerations to make while developing an illumination system. Although the intensity of the grow light is vital, you need also consider the energy efficiency of the system. Another issue to consider is the consistency of the grow light source. Contact the Global Garden team if you need help determining the optimal lighting arrangement for your business. We’ll be delighted to assist you in identifying the most appropriate goods for your requirements.


Concerning PAR, PPF, and PPFD How to Create the Most Effective Growroom for Your Lights Lesson in Lamps: The Importance of Hanging Heights Watts and Watt-Hour in the Greenhouse: How Much Is Enough?Watts and Watt-Hour in the Greenhouse

DLI (Daily Light Integral) Chart – Understand your plants’ PPFD & photoperiod requirements

What intensity of light (PPFD) to expose particular species to and for how long are important considerations. Light intensity, or more specifically, how densely packed light is with photons, is measured in micromoles per meter squared per second, or mol/m2/s. The unit of measurement is micromoles per meter squared per second. This is referred to as PPFD (Photosynthetic Photon Flux Density). The PPFD of bright light is high, whereas the PPFD of low-intensity light is low. While it is brilliant daytime in a warm and sunny location, the sun’s PPFD level that hits the earth is around 2000.

  • During the darkest of nights, it is close to zero.
  • This implies that certain plants prefer strong sunshine (high PPFD), whilst others prefer less intense sunlight (low PPFD) (low PPFD).
  • Time is also a consideration.
  • In indoor grows, where the light output of a grow lamp and its photoperiod (the length of time the light is on) can be readily controlled, this is very crucial.
  • No matter how modest the grow is, whether it’s a single basil plant on the window sill, a grow tent with LED grow lights and a variety of veggies, or a greenhouse powered by the sun, DLI should be taken into consideration.
  • We’ve made it simple for you to figure out how much DLI exposure your plants are getting depending on the amount of PPFD they receive and the time of day.
  • Adjust the lamp’s height in relation to the plant in order to reach the necessary PPFD values, and then specify how long the lamp should be active for each day of the week.
  • Thanks to Erik Runkle (professor and floriculture Extension specialist in the department of horticulture at Michigan State University) and Dr.
  • A partner in Suntec International Hydroponic Consultants, Lynette has written many hydroponic technical manuals and is the author of various other publications.
  • Both of these scientists need to be commended and thanked profusely.

When computing DLI, the following formula is used: moles m-2s-1 (or PPFD) x (3600 x photoperiod) / 1,000,000 = DLI (or moles/m2/day) = moles/m2/day The photons arriving at a certain area (m2) per second are measured in micromoles (mol m-2s-1) and are expressed as a percentage of the total photons arriving at the region.

1 mole equals 1.000.000 micromoles. 1 hour is equal to 3600 seconds. The Daily Light Integral (DLI) is the product of the number of moles per hour per m2 multiplied by the photoperiod (the number of hours at that intensity).

Erik Runkle:
Crop DLI
Vegetative cuttings (liners) – early 4-6
Vegetative cuttings (liners) – late 6-10
Seedlings (plugs) – early 6-10
Seedlings (plugs) – late 10-15
Shade plants (annuals and perennials) 6-10
Foliage plants 6-10
Potted bulbs 6-15
Stock plants (for cuttings) 10-20
Annual bedding plants 10+
Leafy greens and herbs 12+
Potted flowering plants 12+
Shrubs 12+
Cut flowers 15+
Fruiting vegetables 15+
Dr, Lynette Morgan:
Crop DLI
Violets, orchids, ferns 4-6
Seedlings/cuttings 6-8
Small herbs 10-12
Butterhead lettuce 14-16
Cucumber 20-30
Capsicum 20-30
Eggplant 20-30
Tomatoes 22-30

Mango, peppers, ginger, basil, and lemon are being grown under an LEDTonic Q2 LED grow lamp in a 2×2′ tent. The lamp is roughly 10 feet above the ground “/25 cm above the plants, giving around 300 mol/m2/s of PPFD in the middle of the field. At 18 hours of daylight each day, a DLI of 19.4 is obtained. How to Choose the Most Appropriate LED Grow Light (blog) LEDTonic LED Grow Lights are a new generation of LED grow lights. Example: You’re cultivating cucumbers and want to give them a DLI of around 25.

  • If the lamp is turned down to 15, “It has a capacity of 700 PPFD.
  • Choose a combination that is compatible with your grow setup as well as the minimum and maximum PPFD limitations of your plant(s).
  • The following is an example of how to continue.
  • As an initial example of this, the PPFD map depicts spot-PPFD measurements over a 2×2′ region.
  • As the distance between the lamp and the sensor rises, the released photons disperse across a broader region, resulting in a more uniform light footprint as the lamp’s distance from the sensor increases.
  • For the second quarter, we’ve developed two DLI maps of the Q2: one with a 12-hour photoperiod and another with an 18-hour photoperiod, respectively.
  • DLI map for Q2 (12 hrs photoperiod) DLI map for Q2 (18 hrs photoperiod) Please feel free to leave a remark if you have any other queries.

LED Grow Light Intensity and Coverage Simplified

No matter if you’re new to the booming industry or just new to LED lighting, this rapidly evolving technology may have your head spinning. To get the most out of LEDs, you must first grasp the differences in LEDgrow light intensity and coverage. Even experienced high-intensity discharge (HID) growers have a steep learning curve when it comes to LED illumination measurements. You see, high-intensity discharge (HID) grow lights are pre-programmed with a set of principles that define “quality light.” When choosing between HPSand MH lights, increased wattage automatically translates into high intensity.

LED grow lights are more intricate than traditional grow lights for one simple reason: they are more energy efficient.

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Not only that, but they also emit the precise color spectrum that your plants require while directing those photons precisely into the canopy.

This effectiveness is beneficial to both your budget and the environment. To summarize, it is well worth the effort to learn the intensity and coverage of LED grow lights before purchasing one. Using straightforward and simple language, we’ll guide you through everything you need to know.

What LED Grow Light Intensity Really Means

When we speak about light intensity, we are talking to the volume and brightness of light that is generated. Allow us to dispel one of the most common myths regarding grow light intensity in this context. Watts are not the same as intensity. An electric watt is nothing more than a unit of measurement for electric power. It provides you with information on how much energy your lights use in order to run. The only reason growers equate watts with light intensity is because all high-intensity discharge (HID) bulbs have a very consistent wattage.

LED lights, on the other hand, do not operate in this manner.

In comparison to a low-cost LED grow light of the same wattage, a premium 300-watt LED luminaire delivers better light intensity and higher quality light output.

At first glance, this may appear to be a lot, but bear with us.

Understanding the Metrics of LED Grow Light Intensity and Coverage

You should check for particular parameters when comparing different LED lights while conducting your study. As previously stated, the wattage of LEDs has no bearing on the intensity or coverage of the light they emit. Don’t be concerned with the number of lumens. Lumens are only a measure of a light’s visual brightness; they have nothing to do with how efficiently your plants are able to utilize that light. In order to determine the intensity of an LED grow light, it is necessary to consider several factors.


LED grow light makers design their lights to produce a high amount of useable light with little power consumption. Photosynthetically active radiation, often known as PAR, is the term used to describe this useable light. As you can see, your plants only utilize specific wavelengths of light to perform photosynthesis. These wavelengths are all within the range of 400-700nm, which is the visible light spectrum. As a grower, the amount of light produced by your grow lamp should not be your primary focus; rather, it should be the amount of light produced within the PAR range.

The amount of PAR is measured in micromoles.

Coverage Area

Every LED grow light that you are considering should include information on the lamp’s carbon impact. This refers to the coverage area of the luminaire, which is the square footage of canopy that will be illuminated by the light from the luminaire. In order to determine how many and which lights you will need for your grow room or tent, you must first determine the footprint. However, there is a significant relationship between the intensity of LED grow lights and the area they cover. The inverse square law of light is the term used to describe this relationship.

  • In addition, the light intensity decreases rapidly.
  • After that, you raise the hanging height to a distance of 2 feet from the ground.
  • Isn’t there a significant difference?
  • Not only does the size and lenses of your LED grow light impact the coverage area it provides, but so does the height at which it is suspended.

As a result, while picking a light, it is critical to pay close attention to the hanging heights and coverage area. These metrics provide you with information about the conditions in which your plants acquire the nutrients offered. PPFD. And what exactly is PPFD? I’m glad you inquired.


Because of the inverse square rule, merely knowing how much PAR your grow lights generate is no longer sufficient. The PAR of your LED light merely informs you how many useful photons it emits. The quantity of PAR that actually reaches your plants is a completely other measurement altogether. Photosynthetic photon flux density (PPFD) is an abbreviation. The PPFD measurements of your LED grow light tell you how many PAR photons are hitting your canopy every second of the day. This metric is expressed in micromoles per square meter per second (or umol/m2/s), and it is a unit of measurement.

It is dependent on what you are growing.

Plants that bloom like temperatures between 300 and 600 umols during vegetative development and 800 to 1,000 umols during the blooming stage, for example.

Uniformity in LED Grow Light Intensity and Coverage

Now that we’ve gotten a better grasp on LED light intensity, let’s speak about your coverage area a little bit more specifically. The intensity and coverage of LED grow lights are connected not just by the heights at which they are suspended, but also by the distribution of light. Depending on the exact LED bulb, you may notice a reduction in light intensity towards the outside corners of the footprint when the lamp is turned on. This is why it is so critical to conduct thorough research before selecting the finest LED grow light for your needs.

  • An LED light with a 5′ x 5′ footprint and a photometric power factor (PPFD) that falls inside the appropriate range for your crop is discovered by chance.
  • The difficulty is that the photons hitting a surface directly below the lamp were only measured by the PPFD given by the manufacturer, which was insufficient.
  • When analyzing the intensity and coverage of LED grow lights, pay particular attention to the homogeneity of the light.
  • The data on this map depicts PAR measurements taken at various hanging heights and across a range of surface regions.

Light Intensity and Efficacy

As previously stated, wattage is not a reliable indicator of LED light intensity due to the inefficiency of LED lights that fluctuate in intensity. While the efficacy of high-intensity discharge (HID) lights remains constant, LED lights continuously improve, allowing them to provide more intensity with less energy input. In order to do this, high-quality LED grow lights are incredibly cost-effective over the long term. In addition to having a significantly longer life duration, LED lights have a higher intensity while using around half the amount of energy.

Yet another area in which LED grow lights may help you streamline your grow process.

There is less need to bounce lost light back to your plants because all of the light is focused downward onto the canopy.

You stand to save a large amount of money on your cultivation process, while also benefiting from increased yields and a higher-quality product.

We’ll go through the requirements of your individual grow area and assist you in calculating the benefits of utilizing cutting-edge LED technology.

Light Measurement: Lumens, Lux, PAR and Micromoles – Expert Advice

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Light Measurement: Lumens, Lux, PAR and Micromoles

Do you want to grow your plants indoors? Grow lights are required since a window sill just will not suffice. But which one is the most beneficial to your plants? The majority of people choose the bulb with the most lumens per watt.don’t make the same mistake. This information will help you understand why there are significantly more trustworthy metrics.

Lumens and Lux

People tend to refer to light in terms of the following:

  • When it comes to grow lights, the terms Lumens and Lux aren’t very useful
  • Spectrum, Par, Photons, and Micromoles are really useful.


Lumens are units of measurement for light intensity. One lumen is equal to one candle in terms of light output. It’s a fairly straightforward process. Unfortunately, lumens only refer to the sensitivity of the human eye; they do not provide any information about plant grow lights. Their primary use is to determine how well a lamp will allow you to see in the dark, but that’s about it. Keep in mind that while luminescence is for humans, photosynthesis is for plants.


The number of lumens that fall on a square metre of a surface is represented by the symbol Lux. As a result, an illumination of 50,000 lux corresponds to 50,000 lumens falling on each square metre of surface. The amount of light produced by your grow bulbs is measured in Lux. This will be of use to you:

  • Choose how far away you want your light to be from your plants (see this page for additional information on mounting heights)
  • Get a sense of how light fading works(. (See this page for further information on light deterioration.)

Lux, on the other hand, will not inform you how beneficial a grow light is to your plant. You’ve caught a glimpse of a rainbow. It is obvious that sunlight is composed of a spectrum of colors – also known as wavelengths – that are distinct from one another. Nanometres are used to measure the length of light waves (nm).

  • Humans are sensitive to wavelengths between 500 and 600nm
  • Plants are sensitive to wavelengths between 400 and 700nm (the PAR region)
  • And animals are sensitive to wavelengths between 500 and 600nm.

Plants are particularly sensitive to wavelengths ranging from 400nm to 700nm. The PAR region is a term used to define the wavelengths of light that fall within this range (Photosynthetically Active Radiation). Plants respond well to the following substances in particular:

  • The color blue is used to indicate danger (around 400nm-460nm) This product promotes vigorous vegetative growth as well as deep root development and intensive photosynthesis. The flashing red light (around 580nm-700nm) Photosynthesis, stem development, blooming, fruit production, and chlorophyll production are all aided by this compound.

The vast majority of growers employ dual spectrum lighting, which provides both blue and red light. Other growers use a different lamp for each stage of development, which they alternate between. Plant development is slower with this procedure, but the plants are more developed at the conclusion of the process.

  • It is common for individuals to utilize metal halide lamps (blue light) during vegetative development. Sodium lamps (red light) are the most effective during blossoming.

Photons and Micromoles

Instead of relying on lumens and lux, you’ll get additional information from the photon and micromole counts in the PAR region. Does that make sense? What you need to know is as follows:


A photon is a particle of light that exists in the universe. There are two sorts of photons: photons of light and photons of heat.

  • A blue photon is distinguished by its short wavelength. The wavelength of a red photon is quite long

Your plant is simply concerned with the amount of photons it receives. It requires 8 to 10 photons to attach to a single molecule of CO2 in order for photosynthesis to occur. It has been observed that red light produces more photons than blue light when it occurs. This indicates that it is more beneficial for photosynthesis.

Micromoles (µmol)

The number of photons is measured in micromoles (mol). One molecular weight equals 602 quadrillion photons!


Keep in mind that each photon is a particle of light from the visible spectrum.

This indicates that it is plant-usable light. Typical readings for each light may be found in the table below:

  • A good600W, 230V HPS lamp will emit about 1.8 mol per watt
  • A good600W, 400V HPS lamp will produce approximately 1.9 mol per watt
  • And a good600W, 500V HPS lamp will emit approximately 1.9 mol per watt. 315W 400VCDM (ceramic discharge metal-halide) yields around 1.9 mol per Watt, which is rather good. A good1000W, 400Vlamp produces around 2.1 mol per watt of energy.

The only (slight) issue with micromoles and photons.

The difference between the two methods is that only photons from the PAR range are counted. It is not possible to count photons with wavelengths lower than 400nm (for example, UV-AUV-B) or higher than 700nm (for example, infraredfar red). It has been demonstrated that wavelengths outside of the PAR range have an important impact in plant health:

  • Hormone signaling
  • The formation of useful compounds (for example, essential oils, phytochemicals, and pesticides)
  • And the regulation of hormone levels.

What about Watts and Volts?

When you measure micromoles, you are counting the number of micromoles released per watt. It is possible that, even while a lower-wattage light generates more micromoles per watt, a higher-wattage lamp will nevertheless create more micromoles in total. It’s important to remember that wattage isn’t everything, and to pay attention to the spectrum of light that lights emit as well. Despite the fact that they have a power of 315W, ourCDM lamps provide your plant with different forms of light that other lamps cannot provide.


The majority of growers employ a 230V – 240V light source. 400V grow lights, on the other hand, are more efficient and more constant. They’ll always outperform a 230 – 240V light bulb in terms of brightness. To utilize 400V grow lights, you’ll need either a 400V ballast or a full lighting system.

Measuring protons and micromoles

A quantum meter or an integrating sphere can be used to count the number of photons emitted (aka Ulbricht Sphere). Depending on the bulb, they’ll tell you how many photons are emitted from it each second. This is referred to as the photosynthetic photon flux (PPF), and it is measured in micromoles per second (mol/s) of water. Alex Author’s bioAlex is a member of our Board of Directors! It is his responsibility to identify the best items and maintain the smooth running of the company. His toe remains firmly planted in the marketing pond, as well!

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LED Grow Lights Distance for Cannabis & Other Plants

Growing numbers of growers are switching away from traditional HID and fluorescent T5 grow lights and adopting LED illumination instead. Because LEDs release less heat than high-intensity discharge (HID) sources, the distance between LED grow lights and the canopy differs from that of traditional grow lights. It is also critical to understand how the appropriate grow light distance affects the various stages of plant development. A variety of plants (including cannabis) have varying lighting requirements depending on their growth stage, which is covered in this page in detail.

How To Measure Light for Plants

Let’s quickly review what PAR and PPFD are. In the visible spectrum, PAR (Photosynthetically Active Radiation) is a term that refers to a section of the light spectrum that plants “see” and use for photosynthesis (400nm-700nm). Photographic Photon Flux Density (PPFD) is an indicator of how much light (PAR) a plant gets over an extended period of time. The photosynthesis photon flux density (PPFD) describes the light density received by a plant over time and is measured in micromolesper square meter per second (1).

As the sun shines down on the plants, the energy that is absorbed by their leaves is stored.

The photosynthetic photon flux density (PPFD) is an essential metric because it assists farmers in properly measuring the light intensity required for photosynthesis at the canopy level.

In addition, lights that are too close to the canopy might cause burning, bleaching, stunted growth, or discoloration if they are too bright.

LED Grow Light Distance Chart

Distance from Plant Canopy (meters / inches) Intensity (Lux) PPFD / PAR(μmol/m-2/s-1) Coverage or“Light Footprint” (m²/ ft2)*
2m / 79 inches 955lx 670 7.6m2/ 81.8ft2
1.5m / 59 inches 1692lx 1170 5.0 m2/ 53.8ft2
1m / 39 inches 3663lx 1670 3.0 m2/ 32.3ft2
0.5m / 20 inches 12,500lx 2170 1.5 m2/ 16.1ft2
0.2m / 8 inches 50,300lx 2670 0.5 m2/ 5.4ft2

* The amount of coverage will vary depending on the type of grow lamp utilized. The light coming from the LED source displayed here is not directed by a reflector. Table 1 shows the distance between the LED lighting and the plant canopy (600W LED Grow Light) When placed at various distances from the plant canopy, a 600W LED grow light performs as shown in Table 1. Lighting intensity (lux), photon flux density (mol/m2/s-1 or micromoles per square meter per second), and canopy coverage are all depicted.

Table 1 also illustrates how the distance between two identical 600 watt LED lights affects the amount of light a plant receives, as well as the intensity and “light footprint” or canopy coverage a plant receives.

As a general rule, grow lights should be installed closer to the plant canopy during the vegetative phases of development and higher up (and farther away from) the plant canopy during the blooming stages of growth, unless otherwise specified.

Where Should Grow Lights Be Located?

For seedlings, LED grow lights should be set between 24-36 inches above the plant canopy – however, the height of the light source is dependent on its power (wattage). It’s best to place your LED grow lights at least 36 inches away from your seedlings. This keeps the heat and light intensity levels lower and prevents seedlings from being overheated and drying out. Once the roots have become established and the sprouting process has begun, the lights may be brought closer to the plants (usually within the first 2-3 weeks).

The demand for additional light at this stage of photosynthesis necessitates the use of a light source that is situated closer to the plants.

In order to generate blooms, the upper leaves of the canopy should be between 18 and 24 inches away from the light source.

In most cases, changing the height of the lights during blooming is not essential, depending on the lights and how you want your crop to grow.

How Far Should LED Grow Lights be from Seedlings?

Seedlings are sensitive during their early stages of development and require lower levels of light intensity. This indicates that you should avoid increasing the strength of the treatment too soon, since the seedlings will thrive under a much softer treatment. Grow lights may be safely placed anywhere between 24 and 36 inches above the surface of the soil, depending on the size of the light.

How Far LED Grow Lights Should be From Clones

Cropping or cuttings taken from a mature cannabis plant are used to propagate another plant of the same species, a technique known as cannabis cloning. The distance between the LED grow light and the clones is different from the height necessary for seedlings.

When it comes to clones, they will require a lot of light to get started. With respect to the intensity of the light and the age of the plants, this might range anywhere from 14 and 36 inches from above the top of the plant canopy.

How Far Should LED Grow Lights be for Flowering Plants

Plants’ requirements alter as they mature. Plants reach the blooming stage, often known as the “flowering” stage, once they have completed the vegetative stage. In the case of established plants, they have already reached the point at which they will flourish. In order to maximize flowering time, LED Grow lights should be placed between 16 and 36 inches away from the plant canopy. Moving the grow light closer to the plant will enhance the light intensity, which will allow for greater photosynthesis to occur.

What about the other stages of development?

It is necessary to consider the different phases of growth of plants in order to choose the exact distance between grow lights and the plants (2).

Plant development may be split into three distinct stages: the seedling stage, the vegetative stage, and the flowering stage.

Seedling Stage

LED grow lights should be put higher up from the plants during their early stage as seedlings in order to avoid drying out the soil around the plants. Some gardeners may be tempted to blast seedlings with high-intensity light in order to stimulate rapid development; however, this will not be beneficial until the plants have established themselves. Seedlings are far too delicate at this time and require a more cautious approach than is often used. When plants reach maturity, a higher level of light intensity is necessary to stimulate photosynthesis.

Vegetative Stage

Excessive light is particularly beneficial to plants during their vegetative phases, as it is at this time that they are growing and utilizing photosynthesis to grow at an alarming rate. LED grow lights should be placed closer to the plant canopy if you want to boost the intensity of the light. It is essential to have strong, healthy stems and roots in order to provide a profitable and recurring yield. While increasing light intensity encourages development in the vegetative stage, it is critical to regularly monitor your plants and be on the lookout for any unfavorable symptoms that may be produced by either too much or too little light.

Flowering Stage

Fruit production and stem development both accelerate during the last stage of a plant’s growth cycle, which is also known as flowering. It is best practice to “phase” the transition of plant development from the vegetative to the flowering or bloom stage when the plant grows from the vegetative to the flowering or bloom stage.

Gradually elevate the height of the LED grow lights away from the plant canopy in order to accomplish this (using the height recommendations outlined earlier). Keep a tight eye on the distance, keeping in mind the ideal crop height and blooming requirements for the individual plant/crop in mind.

Adverse Effects of Too Much Light

When a plant, such as cannabis, is exposed to excessive light at any stage of its development, it frequently exhibits indications of discomfort. In view of the fact that LEDs do not generate much heat, the major concern that has to be properly watched is any evidence of “light burn.” Other side-effects of grow lights that are positioned too close to the plant canopy include discolouration and stunted/irregular growth, amongst other things. Both of these conditions must be noticed fast, and the height of the grow light must be changed correspondingly.

In addition, light burn may be distinguished by the fact that the plant veins tint green while the rest of the leaves become yellow.

Grow Light Distance – Cannabis vs. Other Plants

Growers are increasingly turning to LED grow lights for cannabis cultivation as they relocate their crop production indoors, according to a recent study. A further advantage of LED technology for growers is the ability to use particular light spectra to create more focused lighting settings for different crops. Additionally, when comparing LED grow lights to traditional sources, lower power usage, less forward heat, and higher yield over a shorter period of time are all advantages to consider.

As an example, if we compare the crop requirements for salad greens and lettuce with those for cannabis, we can observe that salad greens and lettuce prefer shorter, broader growth, but cannabis prefers taller, narrower development.

Lighting Distance for Traditional Grow Lights

High-intensity discharge (HID) lights like high-pressure sodium (HPS) and metal halide (MH), as well as fluorescent lamps, were commonly utilized in indoor growing applications prior to the widespread adoption of LEDs. These lamps have traditionally had a lower initial purchase price than LED grow lights, making them more economical to acquire and, as a result, more accessible to large-scale indoor growers on a budget. The distance between HID or fluorescent grow lights and the plant canopy should be bigger than the distance between LED grow lights.

For each stage of growth, the distance between grow lights should be adjusted, and the wattage of the grow lights utilized determines the space between them.

Fluorescent Grow Lights

T5, T12, and Compact Fluorescent Lamps are the three (3) most common varieties of fluorescent grow lights used in agriculture. Growers must vary the height of the lamps from the plant canopy in order to reach a desired light intensity level for each kind of plant. One advantage of fluorescent lighting is that it is extremely difficult to create light burn since they do not produce enough heat. Regardless, the amount of light and heat should be carefully managed at all times. For immature crops, a height of around 6-12 inches is a reasonable starting point because they require a higher intensity of light.

It is generally recommended to maintain T5s as close together as possible while keeping an eye out for overheating or drying out as a general guideline.

HID Grow Lights (Metal Halide and High Pressure Sodium – HPS)

Metal Halide (MH) lamps provide a significant quantity of blue light, which is believed to be the most beneficial spectrum for plant development during the vegetative stage (3). For both vegetative and blooming growth, high pressure sodium (HPS) lights are the best choice. In comparison to LEDs, both of these emit substantially more heat, but are significantly less expensive to purchase. The back of your hand may be used to test the heat of HIDs, which is a simple method. This might assist you in determining the appropriate grow light distance.

Although your hand should feel warm, it should not become unbearably so.

Many commercial growers employ 1000W high-intensity discharge (HID) lighting, which is typically installed at a height of 19-26 inches to begin with.

However, because HIDs generate a significant amount of heat, it is vital to avoid heat burn, which may cause serious harm to any plant.

BIOS Plant is a pioneer in LED grow lighting solutions, bringing together more than 50 years of cumulative experience and knowledge.

When it comes to LED grow lights, BIOS’ biology-first and research-based approach is guided by nature as we design and manufacture bright full spectrum LEDs that help plants grow stronger and yield more from seedlings to maturity.

When it comes to LEDs, the BIOS Icarus® series provides tailored light spectrums for greater outcomes, while also allowing for simple plug and play configurations.

Our grow lights are simple to set up and maintain, and they are supported by our continued commitment to assisting our partners with their LED integration.

  1. Y. Park and E. S. Rukkle have published a paper in Science (2018). The impacts of white light-emitting LEDs on plant growth, visual color quality, and photosynthetic photon effectiveness were compared to the effects of blue + red light-emitting diodes. PloS one, vol. 13, no. 8, e0202386. U. Niinemets and T. F. Keenan have collaborated on this project (2012). Luminance measurements used in experiments on light-driven plant plasticity in artificial settings. Three hundred and sixty-sixth Frontiers in Plant Science Nicola S. Pennisi, G. Orsini, F. Blasioli, S. Cellini, A. Crepaldi, A., Braschi, I., Spinelli, F., Blasioli, S., Nicola S. Fernandez, J. A., Stanghellini, C., Gianquinto, G., Marcellis, L., Cellini A., Cellini A., Braschi, I. (2019). The effect of the red:blue ratio provided by LED illumination on the resource usage efficiency of indoor lettuce (Lactuca sativa L.) growing is explored. Scientific reports, vol. 9, no. 1, p. 14127.

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