Tag Archives: flush

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

By Phil Gibson
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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)

Mothers to clones: Happy clones, it’s all about the water

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.

dry cannabis plants

How to Grow Cannabis Plants for Concentrate Production

By Andrew Myers
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dry cannabis plants

While flower is still the most popular way to consume cannabis, the concentrates market is booming. Some predict concentrates will be nearly as popular as flower by 2022, with an estimated $8.5 billion in retail sales. That’s a lot of concentrates and, chances are, cannabis producers are already feeling the pressure to keep up.

Concentrates refer to products made from processing cannabis – often resulting in much higher THC or CBD percentages. The category includes oils, wax, dabs, shatter, live resin and hash. Consumers are increasingly drawn to these cannabis products for their near-immediate and intense effects. They’re often consumed through vaporization, dabbing or sublingual absorption and are sometimes favored by those who want to avoid smoking. Cannabis growers who have traditionally focused on flower yields may decide to prioritize quality and potency levels in order to tap into these changing consumer tastes.

What Growers Should Focus on to Produce High Quality Concentrates
We’ll let you in on a little secret: making good concentrates starts with good flower. If you’re starting with low-quality flower, it’s impossible to create a high-quality concentrate. Whatever qualities inherent to the flower you’re starting with will be amplified post-processing. So, really, the concentrate-making process starts at the seedling level, requiring the right care and attention to coax out the results you’re looking for.

Tetrahydrocannabinol (THC), just one of hundreds of cannabinoids found in cannabis.

But what makes good flower? While this can be a subjective question, those producing concentrates generally look for flowers with big, abundant trichomes. Trichomes are the small, dewy structures found across the cannabis plant on buds, leaves and even the stem. They’re responsible for producing the plant’s cannabinoids and terpenes – the chemical compounds that give a strain its unique benefits, aroma and taste. Evolutionarily, trichomes attract pollinators, deter hungry herbivores and provide some defense against wind, cold and UV radiation.

Generally, trichomes indicate how potent the flower is. Plus, what we’re most often looking for when making concentrates is higher cannabinoid and terpene profiles, while also ensuring absolute safety.

What measures can growers take to produce crops that are ideal for concentrate production? Start with the following:

Avoiding Contaminants
Just like you would wash your fruits and vegetables before consumption, consumers want to be sure there’s no dangerous residuals in the concentrate they are ingesting. Growers can avoid any post-process residuals by taking a few key steps, including:

  • Photo: Michelle Tribe, Flickr

    Cutting out the pesticides. Any pesticides that are on your flowers before they go through processing will show up in your concentrates, often even more – you guessed it – concentrated. This is a serious health concern for consumers who might be sensitive to certain chemicals or have compromised immune systems. It’s dangerous to healthy consumers, too. Rather than spraying hazardous chemicals, growers could consider integrated pest management techniques, such as releasing predatory insects.

  • Limiting foliar spraying. Some growers will use foliar spraying to address nutrient deficiency or pest-related issues through delivering nutrients straight to the leaves. However, this can also result in contaminated concentrates. If you really need to spray, do it during the vegetative stage or investigate organic options.
  • Taking the time to flush the crop. This is a critical step in reducing potential contaminants in your concentrate, especially if you’re using a non-organic nutrient solution or fertilizer. Flushing simply means only giving your plants water during the final two weeks of flowering before harvest, resulting in a cleaner, non-contaminated flower and therefore a cleaner concentrate.

Perfecting the Indoor Environment
When cultivating cannabis indoors, growers are given ultimate control over their crop. They control how much light the plants receive, the lighting schedule, temperature and humidity levels. Creating the ideal environment for your cannabis crop is the number one way to ensure healthy plants and quality concentrates. There are many factors to consider when maintaining an indoor grow:

  • Temperature regulation. Trichomes are sensitive to temperature changes and start to degrade if they’re too hot or too cold. To maintain the best trichome structure, you’ll want to maintain an ideal temperature – for most strains, this falls between an idyllic 68 and 77 degrees.
  • Adequate light. For plants to perform photosynthesis indoors, they’ll need an appropriate light source – preferably one that is full-spectrum. Full-spectrum LEDs are able to closely replicate the sun and provide ample, uniform light to your crop. Another selling point for LEDs is their low heat output, making it much easier for growers to regulate ambient heat.

    dry cannabis plants
    Rows of cannabis plants drying and curing following harvest
  • CO2. Another necessary ingredient for photosynthesis is CO2. Providing your indoor crops with CO2 can boost plant size and yields and, therefore, provides more surface area for trichomes to develop and thrive.
  • Cold snap prior to harvest. Some growers rely on this age-old tactic for one last push before harvest – lowering their temperature for a few days right at the end of the flower cycle. They believe this puts the plants into a defense mode and will produce more trichomes in order to protect themselves.

Following Best Practices Post-Harvest
You made it to harvest – you’re almost done!

When harvesting and storing your plants, handle them with care to reduce damage to trichomes. If you’re planning on immediately making concentrates, you can move forward to the drying and curing process. If you’re going to wait a few weeks before processing, freeze your plants. This will preserve the cannabinoid and terpene profiles at their peak.

As the cannabis industry continues to expand, more consumers are likely to reach for concentrates at their local dispensaries. It makes sense that businesses want to diversify their offerings to satisfy customers looking for the most effective way to consume cannabis. As with any cannabis-derived product, producers will want to prioritize quality and safety – especially in the concentrate market.