Tag Archives: ultraviolet

November 8, 2022

The 3-Legged Stool of Successful Grow Operations: Climate, Cultivation & Genetics – Part 2

By Phil Gibson

This is Part 2 in The 3-Legged Stool of Successful Grow Operations series. Click here to read Part 1 and stay tuned for Part 3 coming next week.

Aeroponic and hydroponic systems use zero-soil, so water is effectively our media and our transport mechanism for nutrition. Ideally, you start with clean, fresh water with “nothing” in it. Nothing in this case means no heavy metals, pesticides, bacteria or pathogens. There are some scary words in there so let’s talk through the best ways to get to “nothing.”

The first place to start is by testing your source water, whether it is surface, well or municipal water. This will give you an initial idea of how “empty” your water is. Water supplies shift over time, so it is also a very important input to monitor over time with annual or bi-annual testing. Clean water is the essence of success for aeroponics and a great way to lower your cost of production. With proper design and management, you can recycle and reuse 95%+ of the water you draw into your facility.

Reverse Osmosis (RO)

RO is the most common way to clear your incoming water. The process uses pressure filtration by forcing your water through a series of filters or meshes that block or extract large particles, organics and metals. Normally this is 98%-99% efficient. These systems do require attention and maintenance as they do have filters that are required to be changed regularly depending on the clarity of your original water source and the type of material filtered. This accomplishes a lot of your water clearing process to empty the balloon, but it does not clear the pesky biologicals or pathogens. RO is covered in detail in our “You are what you drink” webinar so look that over for a deeper explanation. There are a wide range of relatively low-cost suppliers based on capacity and filtration efficiency. From an operations standpoint, the key is to understand the filter replacement cycle and cost of replacement.

Ultraviolet Light (UV)

UV light can be used to clear organics and pathogens from water. The primary use is to clear origin water but it is also especially important for recovered water that you save from the humidity in your grow rooms. More on this below. One has to be cautious about the use of UV light. It will cause sunburn and eye damage with exposure so handle this resource with care. After RO & UV treatment, input water should be an empty balloon ready for the addition of your perfect nutrient salt recipe. There are a wide range of low-cost UV lighting solution suppliers from which to choose and they are easy to find.

Dehumidification & Recovery (DEHU)

Early root follicles: Reaching for first nutrients

The number one way to conserve water in an accelerated growth aeroponic grow room is to recapture the humidity that is transpired into the air as the plants grow. While DEHU water is effectively distilled water (or clear of particulates), it can be full of healthy little bacteria or pathogens than may be transported through air or residing in the equipment filters. Clearing these with UV light normally makes this water directly reusable in your fertigation systems. Not all dehumidifiers are perfect. Some metals used in their construction can leach into the recovered water, so this is worth a deeper look as you create your complete water system. Air treatment suppliers are covered in Part 1 of this series.

Used Fertigation Water, or “Flush”

At the start of the flower cycle, take your clean water (the empty balloon) and add your perfect nutrient salt flower recipe and deliver it to your plants. Over the grow cycle from flower to harvest, your plants will use portions of your nutrients and your balloon contents will drift from your target recipe you’re your desired cycle, clear or flush your reservoirs and reset your recipe by refilling your balloon to your exact targets. The exiting nutrient-rich “flush” water can also be recycled into your source water feed since the salts and metals present can be cleared from the mixture through the same RO process that your source water goes through. The end result is perfectly good recycled water savings.

Oxygen Reduction Potential (ORP)

Healthy roots reach for water: Early veg when plants get rolling

ORP is a measurement of an oxidizing agent. Oxidizing solutions are a common and inexpensive method of disinfecting water before and during use in hydroponic systems. Oxidizers can be used to monitor and deal with the “cleanliness” of a nutrient water solution while it is in use. Several oxidizing agents exist with the most common being: hydrogen peroxide, chlorine, ozone and chlorine dioxide. The characteristics of each of these agents and how they interact with the organic matter in solutions is different. The ideal concentrations to use in each situation to kill or control pathogens is unique and one of the topics covered by our “Letters from the AEssenseGrows plant science team” on our website. That deep dive is the subject of another paper.

When you take all of these subjects together and they are done right, you should be able to recycle 95% of your source water with a professional water treatment & recycling system.

Here, I would like highlight the ultimate water hero: Ashley Hubbard, director of cultivation at RAIR Cannabis. For a quick tour of her water treatment and recovery room, see here. No one that I know manages water better than RAIR Cannabis and Ashley leads the team there.

To download the complete guide and get to the beef quickly, please request the complete white paper Top Quality Cultivation Facilities here.

Stay tuned for Part 3 coming next week where we’ll discuss The Right Build Out.

November 14, 2019

Beyond THC: Encouraging Cannabinoid and Terpene Production with LEDs

By Andrew Myers

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For years, tetrahydrocannabinol (THC) got all the attention. While THC certainly delivers its own benefits (such as relaxation and pain relief), there’s a whole host of other – and often overlooked – compounds found in cannabis with important benefits as well. THC is truly only the tip of the iceberg when it comes to cannabis’s potential.

As the cannabis industry evolves with changing consumer tastes and developing medical research, growers may employ techniques to boost cannabinoid and terpene profiles in their harvests – beyond merely focusing on THC. Advanced LEDs allow growers to elicit specific biological responses in cannabis crops, including increased concentrations of these naturally occurring chemical compounds.

The Foundation of Cannabis’s Effects
Whether used medicinally or otherwise, cannabis has changed our society and many of our lives – and there’s a collection of naturally occurring chemical compounds, known as cannabinoids and terpenes, to thank.

The cannabinoids THC and CBD are the most common and well-researched, however they are accompanied by more than 200 additional compounds, including cannabinol (CBN), cannabigerol (CBG) and tetrahydrocannabivarin (THCV), among others.
The cannabis plant also contains terpenes. These structures are responsible for giving flowers (including cannabis), fruits and spices their distinctive flavors and aromas. Common terpenes include limonene, linalool, pinene and myrcene.

Both cannabinoids and terpenes are found in the cannabis plant’s glandular structures known as trichomes. Look closely, and you’ll notice trichomes coating the cannabis flowers and leaves, giving the plant an almost frosty appearance.

macropistil/trichome — A macro view of the trichomes and pistils on the plant

Trichomes – which are found across several plant species – are a key aspect of a cannabis plant’s survival. The specific combination of metabolites produced by trichomes may attract certain pollinators and repel plant-eating animals. Moreover, trichomes (and specifically THC) may act as the plant’s form of sunscreen and shield the plant from harmful ultraviolet rays.

While they play an essential part in the cannabis plant’s lifecycle, trichomes are volatile and easily influenced by a range of environmental factors, including light, heat, physical agitation and time. Therefore, environment is a defining variable in the development of these important structures.

How LEDs Support Cannabinoid and Terpene Development in Crops
Spectrally tunable LEDs give indoor cannabis growers unparalleled control over their crops. As research has expanded about plants’ responses to the light spectrum, growers have discovered they are able to elicit certain physiological responses in the plant. This phenomenon is called photomorphogenesis. At its root, photomorphogenesis is a survival tactic – it’s how the plant responds to miniscule changes in its environment to increase the chances of reaching full maturity and, eventually, reproducing. While cultivated cannabis plants won’t reproduce at an indoor setting, growers can still use the light spectrum to encourage strong root and stem development, hasten the flowering process and the development of bigger, brightly colored flowers.

It makes sense that using the proper light spectrums may also have an impact on the production of specific cannabinoids and terpenes – an important factor when responding to highly specific consumer needs and desires, both within medical and adult-use markets.

Here are a few more reasons why utilizing full-spectrum LEDs can lead to higher quality cannabis:

Lower Heat, but the Same Intensity.
When compared to HPS, fluorescent and other conventional lighting technologies, LEDs have a much lower heat output, but provide the same level of intensity (and often improved uniformity). This represents an enormous advantage for cannabis cultivators, as the lights can be hung much closer to the plant canopy without burning trichomes than they would be able to with other lighting technologies.
UV Light. Cannabinoids and terpenes are part of the cannabis plant’s natural defense mechanism, so it makes sense that lightly stressing plants can boost cannabinoid and terpene numbers. Some studies illustrate an increase in UV-B and UV-A light can lead to richer cannabinoid and terpene profiles.¹ It’s a fine line to walk, though – too much UV can result in burned plants, which leads to a noticeable drop in cannabinoids.
Full-Spectrum Capabilities. The cannabis plant evolved over millions of years under the steady and reliable light of the sun. Full-spectrum is the closest thing to natural sunlight that growers will be able to find for indoor growing – and they’ve been shown to perform better in terms of cannabinoid development. A 2018 study titled “The Effect of Light Spectrum on the Morphology and Cannabinoid Content for Cannabis Sativa L.,” explored how an optimized light spectrum resulted in increased expression of cannabinoids CBG and THCV.²

This is the most important tip for indoor growers: your plants’ environment is everything. It can make or break a successful harvest. That means cultivators are responsible for ensuring the plants are kept in ideal conditions. Lights are certainly important at an indoor facility, but there are several other factors to consider that can affect your lights’ performance and the potency of your final product. This includes your temperature regulation, humidity, the density of plants within the space, CO2 concentration and many other variables. For the best results, your lights should be fully aligned with other environmental controls in your space. Nothing sabotages a once-promising crop like recurrent issues in the indoor environment.

solsticegrowop_feb — Indoor cultivation facilities often use high powered lights that can give off heat

Cannabinoids and terpenes take time to develop – so cultivators will want to avoid harvesting their plants too early. On the other hand, these compounds begin to degrade over time, so growers can’t wait too long either.

Cultivators seeking potent cannabinoid and terpene profiles must find a happy medium for the best results – and the best place to look is where cannabinoids and terpenes develop: the trichomes. With a microscope, cultivators can get up close and personal with these sparkly structures. Younger plants begin with clear trichomes, which eventually become opaque and change to amber. Once your plants show amber-hued trichomes, they’re ready for harvest.

The truth here is that there’s no perfect formula to elicit show-stopping cannabinoids and dizzying terpenes with every harvest. A lot of cannabis cultivation is based around trial-and-error, finding what works for your space, your business and your team. But understanding the basics around indoor environmental controls like lighting and temperature – and how they can affect the development of cannabinoids and terpenes – is an excellent place to start. Using high quality equipment, such as full-spectrum LED lighting can boost both cannabinoid and terpene production, resulting in richer, more potent and higher quality strains.

References:

Lyndon, John, Teramura, Alan H., Coffman, Benjamin C. “UV-B Radiation Effects on Photosynthesis, Growth and Cannabinoid Production of Two Cannabis Sativa Chemotypes.” August 1987. Photochemistry and photobiology. Web. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1751-1097.1987.tb04757.x?&sid=nlm%3Apubmed
Magagnini G., Grassi G., Kotiranta, S. “The Effect of Light Spectrum on the Morphology and Cannabinoid Content of Cannabis sativa L.” 2018. Medical Cannabis and Cannabinoids. Web: https://www.karger.com/Article/FullText/489030

July 31, 2019

Keeping Your Environment Clean: Preventative Measures Against Contamination

By Jeff Scheir

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For years we have heard about and sometimes experienced, white powdery mildew when growing cannabis. It is a problem we can see, and we have numerous ways to combat it. But now more and more states are introducing regulatory testing on our harvests and they are looking for harmful substances like Escherichia coli., Aspergillis Fumigatus, Aspergillis terreus, … just to name a few. Mycotoxins, mold and bacteria can render a harvest unusable and even unsellable- and you can’t see these problems with the naked eye. How much would it cost you to have to throw away an entire crop?

You bring in equipment to control the humidity. You treat the soil and create just the right amount of light to grow a superior product. You secure and protect the growing, harvesting, drying and production areas of your facility. You do everything you can to secure a superior yield… but do you?

Many of the organisms that can hurt our harvest are being multiplied, concentrated and introduced to the plants by the very equipment we use to control the growing environment. This happens inherently in HVAC equipment.

Your air conditioning equipment cools the air circulating around your harvest in a process that pulls moisture from the air and creates a perfect breeding ground in the wet cooling coil for growth of many of the organisms that can destroy your yield. As these organisms multiply and concentrate in the HVAC system, they then spew out into the very environment you are trying to protect at concentrated levels far greater than outside air. In effect, you are inoculating the very plants you need to keep safe from these toxins if you want to sell your product.

The cannabis industry is starting to take a page from the healthcare and food safety industries who have discovered the best way to mitigate these dangers is the installation of a proper UVC solution inside their air conditioning equipment.

Why? How does UVC help? What is UVC?

What is Ultraviolet?

Ultraviolet (UV) light is one form of electromagnetic energy produced naturally by the sun. UV is a spectrum of light just below the visible light and it is split into four distinct spectral areas – Vacuum UV or UVV (100 to 200 nm), UVC (200 to 280 nm), UVB (280 to 315 nm) and UVA (315 to 400 nm). UVA & UVB have been used in the industry to help promote growth of cannabis.

What is UVC (Ultraviolet C)?

The entire UV spectrum can kill or inactivate many microorganism species, preventing them from replicating. UVC energy at 253.7 nanometers provides the most germicidal effect. The application of UVC energy to inactivate microorganisms is also known as Germicidal Irradiation or UVGI.

UVC exposure inactivates microbial organisms such as mold, bacteria and viruses by altering the structure and the molecular bonds of their DNA (deoxyribonucleic acid). DNA is a “blue print” these organisms use to develop, function and reproduce. By destroying the organism’s ability to reproduce, it becomes harmless since it cannot colonize. After UVC exposure, the organism dies off leaving no offspring, and the population of the microorganism diminishes rapidly.

Ultraviolet germicidal lamps provide a much more powerful and concentrated effect of ultraviolet energy than can be found naturally. Germicidal UV provides a highly effective method of destroying microorganisms.

To better understand how Steril-Aire UVC works, it is important to understand the recommended design. Directed at a cooling coil and drain pan, UVC energy destroys surface biofilm, a gluey matrix of microorganisms that grows in the presence of moisture. Biofilm is prevalent in HVAC systems and leads to a host of indoor air quality (IAQ) and HVAC operational problems. UVC also destroys airborne viruses and bacteria that circulate through an HVAC system and feed out onto the crop. HVAC cooling coils are the largest reservoir and amplification device for microorganisms in any facility.

For the most effective microbial control, UV germicidal Emitters are installed on the supply side of the system, downstream from the cooling coil and above the drain pan. This location provides more effective biofilm and microbial control than in-duct UVC installations. By irradiating the contaminants at the source – the cooling coils and drain pans – UVC delivers simultaneous cleaning of surface microorganisms as well as destruction of airborne microorganisms and mycotoxins. Steril-Aire patented this installation configuration in 1998.

The recirculating air in HVAC systems create redundancy in exposing microorganisms and mycotoxins to UVC, ensuring multiple passes so the light energy is effective against large quantities of airborne mycotoxins and cleaning the air your plants live by.

Where are these mycotoxins coming from?

Aspergillus favors environments with ample oxygen and moisture. Most pre-harvest strategies to prevent these mycotoxins involve chemical treatment and are therefore not ideal for the cannabis industry.

Despite the lack of cannabis protocols and guidelines for reducing mycotoxin contamination, there are some basic practices that can be utilized from other agricultural groups that will help avoid the production of aflatoxins and ochratoxins.

When guidelines are applied correctly to the cannabis industry, the threat of aflatoxin and ochratoxin contamination can be significantly reduced. The place to start is a clean air environment.

Design to win

The design of indoor grow rooms for cannabis is critical to the control of airborne fungal spores and although most existing greenhouses allow for the ingress of fungal spores, experience has shown that they can be retrofitted with air filters, fans, and UVC systems to make them relatively free of these spores. Proper designs have shown clearly that:

Prevention via air and surface disinfection using germicidal UVC is much better than chemical spot treatment on the surface of plants
High levels of air changes per hour enhance UVC system performance in reducing airborne spores
Cooling coil inner surfaces are a hidden reservoir of spores, a fertile breeding ground and constitute an ecosystem for a wide variety of molds. Continuous UVC surface decontamination of all coils should be the first system to be installed in greenhouses to reduce mildew outbreaks.

UVC can virtually eliminate airborne contaminants

Steril-Aire was the first and is the market leader in using UVC light to eliminate mold and spores to ensure your product will not be ruined or test positive.

Mold and spores grow in your air handler and are present in air entering your HVAC system.
Steril-Aire UVC system installs quickly and easily in your existing system.
The Steril-Aire UVC system destroys up to 99.999% of mold/spores.
Plants are less likely to be affected by mold…with a low cost and no down time solution.

It’s time to protect your harvest before it gets sick. It’s time to be confident your yield will not test positive for the contaminants that will render it unusable. It’s time to win the testing battle. It’s time for a proper UVC solution to be incorporated throughout your facilities.