Good afternoon, I am Michael Martin, the horticultural consultant for AUVL. I would like to ask, concerning horticultural lighting (both supplemental and sole-source lighting) what is the thing that you feel you understand the least but would like to know more about?
Thank you and I look forward to hearing from you,
Michael
Why is supplemental lighting so important? Why aren’t @growopowners and @mastergrowers incorporating more side lighting and drop lighting into their current lighting arrays? What are your thoughts?
HI Nick,
Supplemental lighting is extremely important in maintaining a constant daily lighting integral (DLI) as well as being useful in lengthening the photoperiod (day length). The DLI is the number of moles of photosynthetically active photons (400 to 700nm) that reach a given area, usually 1 square meter, per 24 hr period. For cannabis there are reported DLI values in the 40’s and 50’s; this is a great deal of light and a few rainy or over cast days can greatly reduce amount of light your plant receive, slowing their growth. By adding supplemental light you can ensure constant and consistent application of light during the growing cycle helping to produce a healthy crop in a timely manner.
As for side lighting, drop lighting and intra-canopy lighting - I am not really sold on their benefits. I read conflicting research concerning their benefit but based on plant growth and physiology, the foliage at the top of the plants usually photosynthesize at higher rates than leave near the bottom of the plant. The foliage at the bottom are shaded but are also older and their photosynthetic mechanics are not as efficient.
Hi Michael,
Was hoping to get a professional feedback if you don’t mind.
I am currently equipping 2 greenhouses in subtropical Australia
Solar exposure data (BOM) - Weather Data temporarily unavailable
Average Humidity: 71%
Targeting to supplement for 350-450 uMole for vegetative state only. Thinking to invest in LED.
Do I need supplemental lighting at all in this climate? Is LED will be most economical in long run?
Cheers
Hi Nikita,
I’ve worked with some greenhouse facilities throughout Australia, and regardless of climate, supplemental lighting is imperative for achieving optimal DLI and timely growth into flowering phase.
LED is the best technology available today, however has only been fine tuned in recent years for high yield, efficacy and reliability.
That being said, there is still a lot of LED’s on the market that do not have the correct spectrum for plants and don’t last more than a year or two, so you must be careful when considering the right choice.
Also, if your focusing on lighting for vegetative stages only, you will need more of the 400 - 500 nm, otherwise known as ultra-violet blue which drives more photosynthesis of chlorophyll A. The best way to achieve this is to use a custom LED.
Hope this helps and happy to chat some more.
Cheers
You will definitely need supplemental lighting for photoperiod and DLI maintenance. LED is absolutely the way to go. With the 0 to 10V dimming capacity, you can integrate with controllers to significantly reduce your power demand. I set up a system that saved grower 83 percent on power compared to HPS system (using Micro-Grow controller and PAR setpoints).
Share your dimensions and I can get you specs comparing 3 products that I would recommend for a greenhouse. Technology is finally there. I can find out who is easiest to get to you down under from multiple US companies and some from Asia that would work.
bgandy@sage.lighting
@MicroGrow-Daphne - your system was involved but it is the one that got beat. (awkward lol) The system was running 64 -750 watt DE fixtures that toggled 32 at a time at 700 mmol and 400 mmol setpoints. It was the most efficient HPS management I had seen up to that point. And definitely the way to go for people running HID in a greenhouse.
Has micro-grow got a solution that can output 0-10V dimming signal for LED? We used a proprietary system at the time for LED.
ps. I’m building a greenhouse in CO soon if you need a place to test a prototype 
Hi Ben,
Thanks a lot for the input.
What nm would you recommend?
We have one of most expensive electricity prices on planet. And finding the most productive/economical sweet spot is the challenge.
Cheers,
Hi Nikita,
400 - 500 nm is ideal for veg.
Have you found a suitable LED yet? We can make a custom length LED bar for you with this wavelength in mind.
Cheers,
Ben
Hi Ben,
Thanks for info. Much appreciated.
What I have the most trouble understanding about the lighting sector in this industry, is the way by which people advertise their arrays. Everyone seems to follow the same trend; describing the efficiency of their diodes, exclaiming that their diodes are the most efficient (when no company yet has proprietary phosphor development contracts), and rudimentary scientific explanations on the spectral capabilities produced by their arrays. Surprisingly, through visiting MJBizCon in Vegas, I learned that this trend extends beyond the internet.
The truth is, everyone has access to the highest efficient diodes available, so it is not an appropriate marketing point. The tricky aspect of this is that within an improper configuration of diodes, as efficiency increases, uniformity decreases. Simply put, with the advancement of dimming capability LED brings, uniformity is of prime focus in optimizing the yield / quality capability of your crop. Optimize uniformity, then tackle spectrometry. This is the proper order.
The truth in regard to spectrum, is no one has even come close to conducting proper scientific experiments with the aim being to find optimal spectrum(s). I think many here would be shocked to see the depth of a properly designed experiment, where the aim is to find optimal spectral environments for specific cultivars, and spectrums which are universally appropriate. With tunable spectrum capabilities, the task of understanding how to optimize spectrometry for cannabis becomes even more intricate. At what phase of the growth cycle does the plant need what spectrum, specifically? What about a specific strain or phenotype implies a desire for a differing spectrum relative to those which seem to work great overall? Is spectrum tuning capability critical to maximizing a crop? Is it a gimmick? Can we find an optimal spectrum which can be applied universally? I don’t know yet.
If my algorithm for defining Photosynthetic Photon Flux Density seems complicated, multiply the difficulty by 5 to understand the complexity of solving spectrometry.
In terms of side lighting, I’ve noticed a few instances where people have side lighting so far from their canopy, that if you turned off their main lighting and waved a quantum sensor along the edges of their canopy believed to be supplemented by side lighting, the reading produced would be 0! Lighting for horticulture is so deceptive. It may look like light is reaching the plants, but very little to none that can be used for photosynthesis is reaching the plants in the specific case I’m describing.
Another issue with side lighting is that people tend to choose straight LED strip diodes for their side lighting. It has been found that these technologies work best when placed very close to the plants. If your side lighting with strips is too far, you might knock side lighting all-together and conclude the practicality of it is a myth. On the other hand, I know of an individual who absolutely rocked his garden with full COB array coverage; both top and side lighting with COB arrays. COBs allow you to further the distance between them and the canopy, while still enjoying all the benefits this next-gen tech brings to your garden.
I recently compiled my algorithm into a single, and much easier to understand presentation for my website. I’ll share it here as a testament to the complexity required to tackle subjects like Photosynthetic Photon Flux Density and Spectrometry. We are gearing up for our soft-launch here on the network, and properly tackling spectrometry is moving up the priority list. We have a team of people with various backgrounds working to develop experiments within practical applications for spectrometry as we speak. Stay tuned!
Algorithm-Completed-PDF-Presentation.pdf (633.3 KB)
Truthfully LED nor HPS is the best choice for cannabis growth, sole source lighitng or supplemental lightning, if you consider all factors such as yield, quality, electrical foot print, extraction, etc. While LED is the most economical in the way of power consumption our R and D (partnered with Revolution Micro) shows that Ceramic Metal Halide combined with square wave low frequency ballast is actually the most economical combination when it comes to your ROI.
So let me given you an explanation as to how and why. For starters CMH technology allows for the high intensity of HPS to be utilized with cooler running temperatures (ambient temp from the bulb) and a full spectrum color range that closely mimics that of the sun. When ran in conjunction with the Revolution Micro DEva our 1000w DE CMH bulb is 22% more efficient on energy consumption over HPS, which puts us within 15% of LED and also runs on average 33% cooler than over HPS saving our customers an average of $18,000.00 a year on their HVC expenses. LED can sometimes create the issue of having to add heat to keep temperatures at a satisfactory level and HPS is like walking into the gates of hell.
In addition to that we specifically focused on cannabis plants with our full spectrum technology allowing us to engineer our spectrum peaks to coincide with chlorophyll A and B stimulation in marijuana and hemp.
Next is UV production. GrowerNick has already asked me one time about our UV level data. I quickly avoided an answer because we believe that our UV levels are the highest of ANY light available in the industry and why we continually separate ourselves from the competition and we wish to keep that data under wraps. Our bulbs emit UVs A, B and C, prompting us to put warning labels on our packaging and inside our packaging as well. All of this was done by design and this is why extreme UV levels are important:
•UV is produced by the Sun Light and is not available in the extreme doses from any other artificial light source other than Cultilux CMH (industry highest)
•UV stimulates cannabis plants to naturally develop defense mechanisms (trichomes) to fight off light sources that are harmful to plant growth. The production of UV allows cannabis plants to build up to 15 different plant-protecting proteins. These proteins enhance the plants pigment, scent, flavor and resistance to diseases.
•Ultraviolet Light is essential in the early stages of indoor plant growth. These rays of UV will strengthen the plants ability to accept greater intensities of light when switching from vegetation to flowering. Without UV production, this transition can potentially cause seedlings to go into shock or slow the growth of the plant.
•Airborne germs and surface mold exist in almost every indoor environment and can sometimes exists at even higher levels than outdoor environments. UV-C plays a large roll in eliminating these substances of indoor pollution and lowering the chance of powdery mildew and also deters a lot of potential pests.
•Overexposure of UV rays can cause skin redness, burns and irritation to the eyes so we highly recommend using eye and skin protecting gear while maintaining your garden.
Last, as this is just a short overview, is final product. What we call results. What else can I say other than CMH technology produces results like nothing we have seen in this industry to date. The same yeild as HPS with half the wattage, EXTREME trichome production (especially with our bulbs, even over other brands of CMH), very high terpene profiles and unmatched oil production at extraction.
I have rambled enough but in conclusion I believe HPS will be phased out completely over time and I also believe LED has its place as well, I just don’t believe its for those looking to maximize their return on their investment. Daily I have HPS users and LED users alike making the switch as this somewhat new technology makes waves throughout our industry. And before anyone jumps me for being a CMH fan boy, which I am, let me say we offer a few full spectrum white light LED options as well that closely match that data on our CMH bulbs and even those options cannot out produce CMH.
I hope this provides some additional information for you to make good decisions in the future. Feel free to message me if you wish to get into greater detail. Happy Growing.
Great response!
I agree with several of your points: namely that HID will ultimately be phased out (the same way incandescent bulbs have been mostly phased out of our homes in the last decade).
As we have spoken about in the past, I am a huge fan of CMH. I think the lights’ abilities to generate ROI are unparalleled. I often write favorably about staggered LED/CMH lighting arrays. What are your thoughts on HID/LED combos, @Cultilightluv?
You and I had discussed this before I made a test run. I was going to implement my LED as side lighting but after some research I felt like you are changing the direction the plant wants to stretch by utilizing side lighting. So I decided to do a small run in a small room with no reflective material, no climate control, no CO2, etc. Just pure bulb performance and have to say I was impressed.
I custom built a rail where I could run 4 of my full spectrum white light 5000k 60w mods in conjunction with a 4000k 315w for veg and then with a 3000k 315w in flower. To say I was impressed is an understatement. A total of 555w of light and nothing else I had a yield of 488 grams of high grade flower and much larger stems and trunks for the size of the plants under just a 315w. EXTREMELY impressive for strictly bulb performance (let me say I have pheno genetics). I had one fan moving air and a couple of pest pads hanging from the ceiling. I wish I could figure out how to attach pics. I will be doing another run once I get moved into the new place in a controlled environment with CO2, etc. Its a great combo and I will continue to try different combinations of wattages and color temps @Growernick.
Nice! I’d love to see pics!
Attaching pics is easy: The upload button is dead center on the toolbar you see when you are writing a reply to a post.
I have had similar results running standalone 315s or combos of LEC/LED. Great lighting solution that is very underappreciated in our industry, IMHO
Not bad for straight bulb performance. 315s need reflective material to really shine…so the next one will be on point.
Very nice! I love the setup! Cool use of unistrut!
Your pics reinforce all the reasons I love CMH! Thank YOU!
Thank-you for such a detailed post! I have heard nothing but positive remarks in regard to growing with CMH technology, particularly in reference to it producing the most optimal spectrum currently available. I can confirm fantastic Cannabis can be produced when grown with a CMH system. Its success in the garden makes me wonder on a few things. One being how CMH technology is affected by temperature-induced chromaticity shift, and if the clearly successful spectrum produced by CMH can be mimicked by an intelligent configuration of LED diodes. We are excited to play around with adding an additional driver to our designs for something like tunable spectrum capability for our arrays, which could include UV supplementation. UV and spectrometry in general is very intriguing, and LED Cultivation is excited to tackle the subject. We do believe solving spectrometry is a long road, though.
We were gifted a 315W CMH bulb at MJ Biz Con, and ran it against our smallest LED array (the 337W ‘Mini’) through our algorithm. Our algorithm essentially showcases the photometric uniformity produced by the test subjects, using proper mathematical relation between PAR measurements in a 3-dimensional framework. Physical testing conditions were a simple 3’ x 3’ squared PVC enclosure wrapped with black / white mylar. Equal mounting distance of 22” for both fixtures. PAR measurements taken with an MQ-500 quantum sensor from Apogee Instruments. I’ve shared my algorithm here on the network as a scientific contribution. It is a fairly complicated process, so if you want more details on how the following metrics are produced, you can find the algorithm’s full presentation on my profile.
We found that our Mini held an improved Averaged Proportional Intensity Variance (APIv) of 35.90% over the 315W CMH. As footprint coverage size increases, and so does the power of the fixture used to cover said footprint, uniformity becomes a trickier task. Our largest model, the 842W Elite, held an improved APIv of 486.27% over the traditional 1000W HPS lighting system. I am curious as to what the photometric uniformity of a 1000W DE CMH bulb would be, and also how the array you shared a picture of would perform when ran through our algorithm. It definitely looks like an interesting configuration.
Efficiency is merely a component of efficacy. That is one of the tricks in the LED world – People love to boast about the efficiency of their diodes. We’ve learned through 2 years of development that more important than the efficiency of diodes, is the configuration of those diodes. Properly measuring the photometric uniformity of a lighting fixture is another component of efficacy, just as the spectrum produced is. LED Cultivation aims to evolve into a product-line which offers optimal efficacy in saturating a given area with photosynthetically active radiation.
Luminaire(s) type(s) used, configuration of those luminaire(s), type / quality of light emitted by those configurations, measurement of light produced by those configurations, translation into practical applications; These are the components we believe constitute the makeup of determining the efficacy of a lighting array for horticultural applications. As we’ve chosen to first focus on photometric uniformity, our measurements translate seamlessly into testing within practical applications, because essentially we are simply measuring the light that can be used for photosynthesis in general. Solving spectrometry is much more difficult, and the translation of spectral measurements into practical applications is not as seamless, because it’s not all of the usable light we’re analyzing, but it is the type , the quality , of that light we are trying to understand, and how these characteristics affect a specific plant.
In summation…
What do you think stands in the way of LEDs matching or succeeding the quality of spectrum produced by CMH technology? Can an intelligent configuration of LEDs produce an optimized spectrum? How could CMH’s spectrum produced be improved?
Considering the differences in heat produced / heat dissipation between CMH bulbs and LEDs (i.e. COBs, Samsung Strips), could temperature-induced chromaticity shift be an issue for CMH?
Do you agree photometric uniformity is an integral component in determining the efficacy of lighting arrays for horticultural applications? Do you believe the solution for optimally saturating large footprints with photosynthetically active radiation is found within a single or even a combination of high-powered light bulbs?
As put in my closing statement of the tutorial for how to use my algorithm: One might even venture to say the importance of spectrum is inversely proportional to the degree by which light spreads from the array, throughout the canopy.
