Continuous Production Systems

Continuous Production Systems: Part I
by Erik Biksa

This is the first part in a series of articles that will enable growers to develop their indoor gardens and management practices so that they can harvest bigger yields per square foot, with the benefit of having harvests every 10 to 30 days.

A lot of gardeners may have raised their eyebrow when reading the above statement. Did the author make a type-o, has the author completely lost it or is there some new strain you don’t know about? Relax; the answer is none of the above. This is not a new growing method by any means, as ingenious growers have been facilitating perpetual harvests for years now. The technique appears to have been pioneered in greenhouse production, namely with leafy greens such as lettuce, herbs and cut flowers.

However, it’s time to take the foundation provided by perpetual harvesting methods pioneered in the greenhouse and build on it to create a high efficiency cropping system for the indoor gardener. Continuous Production Systems (CPS) should keep any gardener happy by creating routine management practices and ensuring that their next harvest is never more than a few days or weeks away from their last one.

The six-inch intake is near crop level, and uses a special HEPA filter designed for use with inline fans to help prevent spores and insects from entering the sealed growing area. It further helps to diffuse cooler air as it enters the growing area, reducing the potential for shocking the plants with cold outside air.

As with many things in life, it all boils down to time management. The CPS grower needs to streamline their cropping schedule and practices for rooting cuttings, vegetative growth, flowering, ripening and harvesting. For CPS systems, the grower is required to maintain separate vegetative and flowering areas. These areas need only to be separate in the sense that they will require different photoperiods and environmental control. Light leaks from one area to another can be disastrous, so careful planning and construction is recommended. This series will outline modern grow room building techniques and practices that will help growers avoid making many common and costly mistakes.

However, before we get too far ahead, let’s talk a little more about what a CPS growing system is, and how you can begin to plan and construct yours.

Tommy Tomato (c'mon, SOMEONE sign up with TommyTomato!! ) grows a variety of cut flowers that typically require 65 days of flowering before they reach maturity. The variety is a short-day flowering plant, so he can induce the flowering response anytime he wants by maintaining his plants in a 12/12 photoperiod. The variety can be grown as single stems by reducing the number of days spent in the vegetative photoperiod (18/6) or can grown as a larger, multiple branched specimen by allowing for more vegetative growth and manipulating the plant’s natural tendency to branch.

Either single stems or larger bushes are capable of producing bunches of high quality flowers; in fact, yields per square foot are similar. The advantage of single stems is less time in vegetation is required, which means they get into the flowering room quicker. Growing larger plants means having a lower numbers of plants to look after, and often with less labor and materials. Remember that when you grow single stems, you need to pack-in the plant numbers per square foot to get a sufficient amount of flowering sites per square foot versus larger, better-branched plants.

Tommy wants to keep the electrical bill low, and only wants to dedicate two 1000-watt lamps for the flowering area and 400 watts of lighting for vegetative growth with either high output fluorescents or with metal halide lighting. The size of the flowering area might range from three feet by two seven feet to 4.9 feet by 9.8 feet {Dunno WHAT he's talking about here, a 1k covers a 4 x 4 in flower. 4 x 8 - or something similar - is what Tommy should be playing with. Paddy} using the two HID lighting systems. For vegetative growth using 400 watts of lighting an area of 2.46 feet by three feet should be sufficient, especially if two levels are constructed by use of shelves and racking.

Alternatively, to reduce venting requirements and allow for efficient CO2 supplement in the vegetative chamber, high output T-5 fluorescents or LED lighting can be used to light the vegetative growing area. LED's emit virtually no heat, and the energy they use is converted into light energy very efficiently. LEDs also consume very little electricity; apparently 45 watts of good quality LED lighting can replace a conventional 250-watt HID system according to some manufacturers. The use of LEDs allows growers to create growth chambers that would not be possible due to size or venting constraints. This series will examine the use of LEDs, and their feasibility in all growth systems including CPS (Continuous Production Systems).

CPS is also well suited to larger, multiple lamp installations and can be adapted to larger applications by following the model outlined in this series of articles.

Tommy prefers to have bigger plants and fewer of them to simplify labor and ensure good yields. He usually grows four plants per 1000-watt lamp, and can continue to use this planting density in the CPS model. So, in total, there will be eight plants in the flowering area at all times, that’s four plants per light. The number of plants maintained in the flowering area can be streamlined over time in a CPS model, for example Tommy may find that he actually yields more by only maintaining six plants in the flowering area.

No matter how many plants he maintains, he will be harvesting a portion of them on a regular basis, and replacing them with new plants that are ready to flower, often on the same day.

Since the variety he prefers to grow requires 65 days of flowering, and he wants to maintain eight plants, Tommy will harvest two plants about every 16 days. So, in this CPS model he will have eight plants that are in four different stages of reproductive growth in the flowering room, dividing his crop into four distinct blocks, each containing two plants.

To supply the CPS flowering room with sizable and healthy plants ready for flowering every 16 days requires maintaining a tight propagation and vegetative growth cycle. To do this, Tommy starts new cuttings every 16 days and allows them the full 16 days to develop a healthy and vigorous root system. At the end of the 16 days of rooting, the cuttings are transplanted, and grow in an intensive vegetative environment for another 16 days. However, as soon as the rooted cuttings were transplanted for vegetative growth, Tommy started new cuttings at the same time that would be ready again in another 16 days to repeat the cycle over again.

In the vegetative area, every 16 days the following occurs:

* New cuttings are started
* Rooted cuttings are transplanted for vigorous production
* Vegetated plants are ready and transplanted for the flowering area

You can fine-tune your own CPS model for more or less frequent harvests with any number of plants. You can run your CPS set-up as tightly as having daily harvests and replacements or space it out to as much as a month a part. You just need to know how long the variety you grow takes to mature, and you can plan from there. Plants that gain more size in flowering are preferred, this way you can grow larger and fewer plants without having to spend too much time in the vegetative growth phase. If your variety produces slow vegetative growth, and does not gain much size in flowering, you can grow greater numbers of smaller plants, or widen the CPS window to 32 days instead of our example of 16 days.

If you widen the CPS window to 32 days in our example you will harvest four of the eight plants every 30 days instead of two of the eight plants every 16 days. You will get similar yields per plant, but the time between harvests will be greater. In the vegetative area, the plants can still root for 16 days, but will then get 32 days of vegetative growth instead of 16. You would also be vegging four plants for 32 days rather than two plants for 16 days.

The vegetative cycle, and the number of plants you maintain in it can be fine tuned over time. The most important thing is that you have the correct number of plants that are the right size for the flowering room available on a scheduled basis (in our example every 16 days) to replace the plants that you harvest on a scheduled and routine basis.

Don’t get a headache thinking too much about this yet, as it will become more apparent and simplified through the CPS series of articles.

As with any indoor gardening project, your success will be the result of a combination of the following factors:

* Having a suitable variety
* Good crop management
* The construction of the growing area
* Level of environmental control (light, air, water)
* Using high quality nutrients, additives and beneficials

In this series, you will be walked in a more or less step-by-step basis into establishing a successful CPS model of your own. Again, this model is only using two 1000-watt lights for flowering and 400 watts of lighting for the vegetative area, although you can adapt the CPS model to larger or smaller endeavors. An alternative light source can be used in the vegetative chamber such as T-5s or LEDs to reduce electrical consumption and cooling requirements. While in the flowering area, use a dimmable 1000-watt lamps or one 600-watt for the early flowering phase and one 1000-watt for the later flowering phase can be used to further reduce electrical consumption and venting requirements. An adjustable light mover could allow for the use only one 100-watt lamp or one 600-watt lamp for the flowering area, although yields per square foot of growing area may be slightly reduced in a trade-off for electrical savings. In some installations, it may be possible to use LEDs as lighting for the flowering area, and this series, we will look at the possibilities.

Before we can start to build anything, we need to carefully source our equipment and think about how we want to manage the growing environment, which includes light, temperature, air movement, CO2 levels and relative humidity.

For lighting, digital/electronic ballasts are an excellent choice. While the initial outlay can be more expensive versus conventional ballasts, the benefits greatly outweigh the extra investment at start up. One of the ballasts pictured is the next generation in HID lighting technology. {It's about the light, not the ballast. Digi ballast are NOT UL listed, and DO emit a very distinct line noise to the cable/electrical guy if he is working near your house. Quality mag ballasts are bullet proof. And virtually fire proof}

The unit runs completely cool to the touch and will automatically cool itself or even shut-off if overheating, all with visual display indicators that tell the grower exactly what the ballast is doing. The unit runs near silent and can be mounted in any position easily, as it weighs less than a book. An additional benefit is that the lamp can operate at distances of up to 75 feet away from the ballast unit. This can be of great benefit to growers, helping to create gardens of any scale, while keeping all lighting equipment in a centralized area. This cutting edge lighting technology also allows the unit to be plugged into any voltage from 90 volts to 270 volts without any changes made to the unit. It detects the input voltage, and strikes the lamp perfectly, bringing it to brilliance within about five minutes.

While conventional core and coil ballasts are inexpensive and have been reliable, electronic and digital ballasts can offer many advantages past their electrical savings and high output. In cooler climates, some growers may actually take advantage of the heat generated by core and coil ballasts to help warm their growing areas in cold months.

High quality air-cooled reflectors will improve the efficiency of any grow room including continuous production systems. They remove heat generated by lamps before it enters the growing area, and reflect the light downward in an intense and equidescent spread.

It is recommended that you get the highest quality lighting system that you can afford. There is no sense wasting the lumens you generate, because you pay for each and every one of them and they directly translate into the output capability of your conventional or CPS indoor garden.

Where short runs of lights are used, for example two lamps in a row, the air-cooling can be orientated directly in-line. Larger installations will require ducting “trees.” The reflectors pictured use a highly reflective aluminum insert that helps even light distribution from the ends as well as the sides of the lamp reflector. Although almost invisible to the human eye, the material is very finely textured to help diffuse light. High quality models feature tempered glass lens for safety and durability, and are hinged to allow for easy access and cleaning. Gaskets ensure that there is a tight seal between the reflector and the lens to prevent grow room air from escaping the area un-filtered.

In-line centrifugal fans are recommended for cooling, as they allow for variable speed control, which is one of the core benefits of this CPS model due to a special control that regulates the fan speed with cooling requirements. Two six inch or eight inch models (exhausts) and one four inch or six inch model (intake) are required for the number and wattage of lights outlined in this model. However, centrifugal fans are available in a range of outputs to suit any sized installation. Note the mounting of the in-line fans in this CPS model. Rubber straps are used to suspend the fans from the ceiling with sturdy hooks. This greatly reduces the noise and vibration associated with fans. This can be especially important when you or other must cohabitate with or near the growing area.

A high quality activated carbon filter is suspended at one corner of the CPS chamber for evacuation of warm and moist grow room air. At the opposite corner a HEPA filter designed for use with in-line fans prevents spores and insects from entering the growing area that might cause problems with crops. Both of these pieces of equipment are essential to ensuring that air coming in and out of the growing area is free from contaminants. To help prolong the life of the carbon filter, the model chosen has a removable and cleanable pre-filter. By cleaning the pre-filter periodically, fewer particulates will enter into the activated carbon matrix, extending the period that the unit can be used before requiring replacement.

For any sized installation, and especially for small to mid scale, but intensive CPS installations, a high degree of environmental control is recommended. At the heart of this model is a fan-speed controller that regulates the output of centrifugal fans based on grower day and night temperature set points. This device is rather ingenious, and should be a welcome addition to any grow room. Instead of having your fans come on full-bore thermostatically, then shutting off, the unit increases or decreases the fan speed as cooling requirements dictate. For example, if the day temperature exceeds the set point, the fans area is activated, but at a low and quiet speed. If this does not cool sufficiently, the unit will increase the fan speed slowly, until the area is cooled back down to the set point. It operates both a tight and soft mode, depending on the level of control you want to maintain.

The intake, exhaust fan (with carbon filter) and air-cooled lighting fan can all be coordinated by the device. Temperature control is very accurate using the remote probe supplied, with little or no significant temperature fluctuations from the grower day and nigh set points.

For safety and ease of use, high quality lighting timers/relays can be purchased pre-wired and are very user friendly. The grower simply needs to connect the two hot wires, ground and neutral (if applicable) to the easy to access lugs inside the unit following the diagram supplied. Now, simply connect this to your 240-volt power source (ensuring that it is safely off first), set the timer, and plug in your lights. These are proven devices that are backed by reputable manufacturers and make installing HID lighting much safer and easier. A lot of these units can be purchased for the same cost as building your own, but without all the guesswork and with added piece of mind.

For an increased degree of safety and reliability in your CPS installation, your timed lighting power relays trigger cord/plug can be connected to an additional controller that prevents hot lamp starts and shuts off the lighting system if the temperature exceeds the grower set-point. With this device, if the power is interrupted by either a power shortage, or by the device (to prevent overheating of the grow room due to equipment failure), the device will wait for 15 minutes after the room is cooled or power is restored before allowing the high power lighting relay to become activated. Conventional ballasts will not start and can be damaged as well as the lamps, if they do not have time to cool between being shut-off and being re-started.

Technologies where plastic films are concerned grow leaps and bounds. There are some excellent choices to be had in selecting a reflective material that reflects the maximum amount of light, while retaining all of the light energy to help the CPS installation operate more efficiently by helping to prevent radiant loss of light and heat energy. Typically, white films have been preferred to apply diffused reflective light, but the reflective film featured has both a silver reflective and a white reflective side, offering a choice. According to the manufacturer, the silver reflective side of this special film helps to convert reflected light into wavelengths that help crops perform better. To ensure light-tight installations, overlap the seams of the film six inches and seal with aluminum tape, as pictured. The reflective material for the walls and ceiling, and the thick heavy gauge reflective white poly for the flooring were carefully sourced from a European manufacturer to ensure that they were food grade materials and would not give off any gases that could be harmful to the crop.

So far, we have talked about some high tech cropping methods and cutting edge growing equipment. In the next few installments in this series of articles, we will see how it all comes together to help create the perfect controllable environment that is at the heart of continuous production systems. There will be plenty more to come on the actual construction of the vegetative and flowering chambers, the installation and management of the controls, ventilation and lighting. Plus, we will talk at some length about CPS management to ensure frequent and abundant harvests including important aspects such as the management of crop nutrients, additives and beneficials.

In the meantime, start to source your gear (lighting, fans, controls, filters) building materials or grow-hut and get ready to start planning your harvests as close together as you can manage. Continuous Production Systems are capable of providing you with as much harvest as you desire, as often as you want it; with a little bit of planning, expense and some work.

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Continuous Production Systems: Part 2
by Erik Biksa

This is the second installment detailing the equipment, construction and management of a CPS (Continuous Production Systems) growth chamber. In part one, we discussed what a CPS system was and learned that we could harvest a portion of our plants every 10 to 30 days by creating routine cropping management practices; constructing a dedicated vegetative growth chamber; and constructing a proportionately larger dedicated flowering room.

CPS is a model that can be applied from small scale to commercial sized growing endeavors. In the future, routine harvests of homegrown produce may be necessary to help ensure a healthy and complete diet, as only freshly grown produce can provide. Basically, CPS will allow for routine and scheduled harvests of a more useable quantity versus larger mono-crop harvests that occur less frequently. This helps to maintain a steady and consistent diet of freshly grown plant material for your health and well being.

LEDs can be very bright and deliver efficient light wavelengths to plants. The diodes can be maintained extremely close to plants helping to improve lighting efficiency and maintaining healthy plant growth. Plants appear black to the human eye under a combination of red and blue LEDs, as no green light is supplied to reflect back from the leaves.

Right now, let’s focus a little more on the physical construction of an efficient CPS environment. Pre-fabricated grow tents are available in a wide range of sizes. The framework typically consists of metal tubing, similar to tent poles, and is well enclosed by a one-piece, zippered covering. The covering is typically light proof and contains a highly reflective material on the inside to maximize artificial lighting intensities inside of the enclosure.

The advantages of these structures include:

* Can be set-up or dismantled within an hour using minimal tools
* Clean and consistent
* Requires minimal or no permanent alterations to the building or room where it is operated
* Reasonably priced
* A variety of sizes available
* Reasonably light-tight and leak proof

The disadvantages of these structures include:

* No custom sizing
* No insulation to buffer temperatures or dampen noise (fans)
* Limited choice of coverings
* Are not intended to support significant weight loads

Note that several suppliers of pre-fabricated grow tents have had some issues with off-gassing of their coverings, so do a little research and make sure that your supplier stands behind their product.

If the situation permits, it is a good idea to insulate the growing area, even if using pre-fabricated growing enclosures. In the case of pre-fabricated grow tents, you can insulate the room(s) that house them.

If you choose to construct your own grow room, you will thank yourself down the road for taking the time to do it right, versus hastily throwing up a grow room, only to have to make major modifications mid-crop because of cut-corners in the initial construction.

If framing your own walls, use fiberglass or stonewool insulation between the joists before sealing off on both sides with six-mil vapor barrier. Special brackets are available to attach to your joists before attaching your sheeting material that help to reduce noises and vibrations by leaving a small gap between the joists and sheeting material.

For custom-built growrooms, make allowances in your final dimensions for your walls to be thick. This accommodates more layers or thicker dimensions of insulative material that helps reduce audible noise and vibrations, and makes controlling the growing environment more efficient.

Different types of insulative sheeting have different “R” values, depending on the thickness of the material and the chemical composition of the material. White Styrofoam boards are inexpensive and come in a variety of thicknesses, typically from ¾ inches to three inches thick. It is easy to cut and work with too.

After applying the insulative sheeting, it is recommended that you affix wood sheeting such as plywood or O.S.B. next. This will allow you to attach your equipment wherever you like on the walls without having to search for joists to anchor into. However, for heavy equipment, anchoring into a joist is always a good idea. Wood sheeting material further helps to reduce noises and better insulate the growing area while providing tough and durable walls.

Whether you used wood sheeting or not, make sure the final layer of covering is a light-tight and highly reflective film. As mentioned in the previous CPS installment, coverings in this model were carefully sourced (from a European manufacturer) to ensure that they were manufactured with food grade materials. The silver reflective side of the dual-sided film was chosen because the film formulation is said to help to improve the spectrum of reflected light, enhancing plant growth. It also has energy efficient properties that help to keep all the light energy inside of the growing area covered with the material. Where the plastic film is joined while hanging on the walls and ceiling, a six inch overlap is recommended, and all joints should be completely sealed off with aluminum tape.

The covering should extend over doorways and duct ports. To create an entrance after covering the doorway, use industrial adhesive zippers to create an opening. Light leaks somewhat through the fabric of the zipper, so a second skin of film can be secured with a continuous perimeter of Velcro over the entranceway. The sheet can be un-velcroed and then the second sheet un-zipped for access in and out of the growing area. The film covering the doorway (and walls) can be secured with lathing to the doorframe to reduce wear, tear and potential damage to the film.

With CPS, it is necessary to maintain separate flowering and vegetative environments continuously. However, with careful construction and planning, they need only be separate in the length of day and complete darkness they maintain. It cannot be stressed enough how absolutely essential it is to prevent light from leaking into the flowering room during the dark phase.

Before you even begin construction, you need to map-out how you will handle the cooling and venting requirements of the growing area (if applicable). For air-cooled lighting and in/out rooms you will need to create an access of suitable diameter for air coming into the area, and air exiting the growing area. Straight runs of rigid ducting help to move air efficiently. For efficient use of space, try to keep your ducting overhead. You can even partition it from the rest of the growing area (like a sub-ceiling) with soundboard if you plan and build carefully.

In the last installment we discussed the importance of filtering the air coming in and out of the area. In this CPS model, a greenhouse HEPA six inch diameter air filter helps keep the air coming into the area clean and free of insects and spores which can lend to cropping issues. The exhaust was scrubbed clean of airborne impurities through a high quality activated carbon filter. It is imperative that the carbon filter be sized correctly to the fan’s CFM output to ensure that it works effectively.

During construction, be sure to seal-up any gaps or cracks between sheathing on the walls, floor or ceiling before covering with a reflective barrier. Expanding foam works great for these applications. Gaps can allow air to leak into and from the room. These gaps provide a gateway for airborne plant diseases and tiny insects such as spidermites. The tiny insects can actually get sucked right in with the breeze created when the exhaust fans create negative pressure in the room when active. Gaps in growroom construction can also create other issues, including light leaks. With CPS environments, it is necessary to continually maintain both flowering and vegetative environments simultaneously. Light leaks into the flowering area during the dark cycle can be disastrous to crops.

In part one we discussed options for lighting in both the flowering and vegetative chambers/rooms. For the bloom phase, HID lighting is preferred because it can deliver very high light intensities over a respectably sized area, and penetrate thick plant canopies. With all artificial lighting sources, light intensity drops significantly with the distance it travels from the lamp. While HID lamps are no exception to this rule, the light they produce maintains intensity for greater distances than LED of fluorescent plant lighting.

LED lighting (light emitting diodes) has been gaining some attention among horticulturalists and researchers. NASA has been experimenting with LED lighting for producing crops beyond earth, and the technology has become available to home gardeners.

LED systems typically consist of a light-board, looking similar to something you may have played with as a child. However, this is no toy. The many individual little diodes affixed to the board can collectively produce very bright light. The individual diodes range from around 0.3 to three watts. Three watt diodes are very rare and exotic. The one watt diodes are found in many high-output LED systems, and would be the minimum necessary individual bulb wattage for anyone who is looking to grow from start to finish using exclusively LEDs. In this CPS model 12 inch by 12 inch boards of 112 individual 0.3 watt LEDs are used to illuminate plants in the vegetative growth chamber.

Each of the 12 inch by 12 inch panels consumes only 45 watts of electricity, and best of all, runs extremely cool. The manufacturer states that each panel can illuminate up to five square feet. In the CPS vegetative chamber model, two panels are combined to illuminate an area smaller than five square feet. The units are surprisingly bright for only consuming 45 watts of electricity each. Discussing lumens with regards to LEDs can be very deceiving, especially when comparing to HID lighting systems. The reason is that HID systems are only producing about 10 per cent to 15 per cent of their total light output in wavelengths that the plants can actually use. Fortunately for growers, the sheer volume of lumens helps to make up for their relatively poor spectrum for plant growth.

LED lighting boards are tailored to produce light in very exacting wavelengths. While they don’t deliver extremely high lumen outputs, each lumen can be used for the photosynthetic response by the plant. For example an LED lighting board may have 40 per cent of the total number of lamps in blue spectrum and 60 per cent of the total number of lamps in the red spectrum. When LED manufacturers list red and blue, they mean exactly that. For example, each red lamp is exactly 650 nanometers, while each blue lamp is exactly 465 nanometers. Exactly what your plants are looking for.

Interestingly, other organisms that depend on plants may need other spectrums to survive. It may be possible to eliminate or reduce certain insects and plant diseases because the light wavelengths they require can be possibly omitted using LEDs.

What this means is not a single lumen of light is not used by the plant. Here’s a very approximate example of comparing LEDs to HID lighting:

* A 90 watt LED (90 diodes times one watt) produces 2200 lumens. We know that the plant can use each lumen, because it is in the correct wavelength, and lets assume 75 per cent of these lumens get to the plant, because the LED fixture can be operated within inches, or even touching the plants. 2200 times 75/100 = 1650 useable lumens for 90 watts of electricity.
* A 400 watt HPS system produces around 50,000 lumens. Lets say 15 per cent of that can be used by the plant for 7500 lumens. We know that the lumens drop with distance traveled, so lets guess that the plant is getting 3000 useable lumens of light for 400 watts of electricity.

So we can see from our very rough approximation from above that each type of lighting system has it’s advantages. Perhaps in this series, we will get our hands on a very high quality light meter and get hard data for comparison. Of particular interest would be the PAR lumens (Photosynthetically Active Radiation).

Again, it is definitely worth mentioning that LEDs give off virtually no heat. This is huge, because it allows people to garden under lights where they could not have before. Traditionally, a significant amount of plant to light clearance is required, as well as the necessity of extracting the heat from conventional lighting systems from the growing area. This means that conventional growth chambers are big and noisy, relative to a few small plants that they may contain. With LEDs it would not be difficult to grow a small crop in your kitchen cupboard because:

* The LEDs can be kept very close to the plants
* The LED fixture is only a couple of inches thick; using minimal vertical space
* Venting requirements are minimal passive venting or only minimal mechanical venting is required.

Only minimal air exchange is required, to evacuate humidity and draw in fresh air. This can be achieved with a much smaller vent fan, similar to the one you might have cooling your computer circuitry. Due to reduced venting requirements, supplementing CO2 levels is simplified and efficient; helping to increase growth rates.

At present it seems that LED gardens will not out-yield HID lit gardens, but LED lighting will allow people to grow in places they could not have before, using very little electricity or peripheral growing equipment such as elaborate ventilation systems. However, with LED technology growing leaps and bounds, and higher wattage diodes becoming available it seems possible that LEDs could be the next wave of lighting in the future.

At any rate, current LED technologies can be incorporated into CPS models to reduce electrical consumption, produce healthy plant growth, minimize venting requirements and allow for the installation of vegetative growth chambers where they might not otherwise be possible.

In our next installment we are going to dial in our CPS model and cropping schedule. As well, we will look at some nutrient management techniques to promote big yields and control plant growth in all phases using cutting edge nutrients, additives, beneficials and electronic measuring equipment.

With the information revealed you will have all the necessary tools and management techniques to operate your own Continuous Production System to ensure yourself a fresh and steady supply of nutrient rich plant material.

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Continuous Production Systems: Part 3
by Erik Biksa

In our last installment we discussed CPS construction details and looked into the benefits of incorporating LED lights into the continuous production system model. The model was able to demonstrate that LED lighting offerd a practical solution to maintaining a vegetative growth chamber in conjunction with a HID lit flowering area. For smaller installations, high output (T-5 or T-8) fluorescent lighting can be used in the flowering area to produce high quality, but slightly lower yielding (versus HID) crops.

The LEDs allowed for a much smaller and tighter space to be used with minimal venting, producing very healthy and high quality transplants for transfer into the rotation of the flowering room. By using LEDs, the vegetative growth chamber plants can be supplemented with CO2 very efficiently because there is little if any heat generated by the LEDs that needs to be vented away. Venting is only required for removal of humidity or as otherwise necessary. The exacting spectrum of the LED fixtures helps to produce firm and squat growth, which are very desirable growth characteristics when gardening under lights.

This cutting edge CO2 generator uses water cooling to remove most of the heat created when fossil fuels are burned cleanly and efficiently to produce carbon dioxide. This significantly improves the efficiency of CO2 supplementation in the growing area and minimizes exhaust requirements or air-conditioning. The unit runs cool enough to wall mount.

In this CPS model it has been recommended that the plant varieties selected to enter CPS rotations are able to gain a significant amount of stature in the early flowering phase, so less time is required in the vegetative growth phase. During a typical two week vegetative growth period following the successful rooting of cuttings or well developed seedlings, the goal is to help the plant develop as many healthy branches in an equidescent pattern from the light source as possible. This allows for the use of fewer plants to fill a given floor area with as many healthy flowering sites for high yielding crops of fruits and flowers as possible.

If the variety you choose to grow does not fit this growth pattern, more plants can be used per square foot, helping keep the time required for vegetative growth minimal. Where greater numbers of plants are required, maintaining mother/donor plants at all times is recommended, so a fresh crop of cuttings can be started at any time as required by the growers CPS schedule.

Alternatively, if the variety you prefer to grow has a slower vegetative growth rate and you wish to maintain fewer plants, you will need to adjust your CPS schedule. Instead of the typical two weeks of vegetative growth the rooted cuttings receive following the cloning phase, you can double the vegetative growth period to a total of four weeks.
When you adjust your vegetative growth phase, for example to extend it to four weeks instead of two, it will need to echo in your flowering cycle or you may choose to further divide your CPS operation to include a multi-stage vegetative growth chamber. A multi-stage vegetative growth chamber is better suited to installations running multiple lamps in the vegetative growth phase. The simplest way, however, is to change your schedule in the flowering area.

In our examples, we have discussed a two week rotational cycle. Every two weeks new cuttings are taken for rooting; freshly rooted plants are transplanted for vegetative growth; plants finished vegetative growth are transplanted into the flowering area; and mature plants are picked or harvested. By performing these scheduled tasks, the grower ensures a consistent harvest ever two weeks. In our example (as outlined in the first installment) the grower is harvesting two large five gallon plants in containers every two weeks.

So if we need to veg for four weeks to get out plants to the right size and number of branches (versus increasing the number of smaller plants) and because we do not have the space and/or desire to create a multi-staged vegetative growth phase, we will need to change our rotational cycle from four weeks. The main affect this will have is that at the end of the line in the flowering room, instead of harvesting two plants every two weeks, we might harvest four of the same sized plants, but every four weeks. This allows us to accommodate for the longer vegetative growth period. In the end, we will harvest about the same amount of fruits and flowers per month, but the difference is that we will be receiving our harvest every four weeks instead of every two weeks. As a good friend likes to say, “six in one hand, half a dozen in the other.”

Besides some of the obvious advantages in increasing your harvest frequency following a CPS model, a great advantage is that you, the grower, are in a really unique position to learn about your particular crop. Because you will have several plants of the same variety in all stages of growth/development at the same time, it will be easier for you to learn their exact growth patterns and needs on a week to week basis rather than a month to month or even cycle to cycle basis. Maintaining this overview of your crop at all times should really allow you to dial-in your feeding program. Even if your next projects are not CPS, the insights you will have gained on the needs of your crop on a week to week basis will carry over, allowing you to always yield better because you have developed a higher understanding of the needs of your plant at different times and you know what things will look like two weeks after you feed a particular solution or provide a particular treatment.

You can make-do with a “one size fits all” feeding schedule where, for example, all plants in the flowering room are fed the same nutrients all the time. A half a step better would be that they are fed the same nutrients all the time, but at different overall feeding strengths. Optimally, you will create and follow a nutrient feeding program that is looking after the nutritional requirements of your crop on a week to week basis. With CPS models, the goal is to isolate the individual needs of the plants on a weekly developmental basis, optimizing growth rates and ultimately yields as plants are treated according to the distinct stage of growth they are in.

Each plant variety is different, and the growing medium and style of management will also affect what the ideal nutrient regimen might be for any individual situation. However, the following is a rough outline that can be used to model an advanced nutrient feeding program for your CPS endeavors:

Week One: (Transition)

* Take advantage of the plants accelerated growth rate at this time, to gain as many healthy branches and flowering sites per plant that have access to intense light as possible.
* Base nutrient strengths are lower to encourage the plant to use up excess stored nitrogen.
* Foliar sprays can be particularly advantageous at this time; combine potassium silicate solutions and plant immune system activators. Kelp based products will also help to improve growth rates and reduce the possibility of a trace element deficiency.
* Build as big a root system as possible. Inoculate or treat you crop with a variety of beneficial fungal and bacteria. Look for products that contain “super strains” of bacteria as these have been isolated and created in labs to provide the strongest impact for your plants.
* If your plants are already large enough, and extra size gain is not desirable, consider using an additive that will halt vertical growth. Some are better than others, and always apply with caution. If used correctly, you can actually reduce your flowering cycle by a week or two.
* Avoid using B-Vitamin supplements at this time.

Week Two:

* If flowers have begun to form, you can start to add a bloom booster to your nutrient regimen, although at a smaller dosage rate. Boosters containing amino acids are advantageous because they are supplying the plant with reduced nitrogen (not “less” nitrogen, but a form the plant creates).
* Continue foliar applications of silicate and immune system activators.
* Keep applying a variety of benefical inoculants to improve the health of the plant and to develop as big a root system as possible.
* Reduce nitrogen levels in base nutrient applications, based on the level of flower or fruit development. If plants appear to still be producing structural growth, supply them with the necessary nitrogen.
* Do not over apply nitrogen at this phase or it will slow flower development and make for soft plants that are more susceptible to diseases and insects.
* Carbohydrates and humic acids will help to keep things healthy, as well as provide a food source for beneficial bacteria and fungi in the root zone.

Week Three:

* With most varieties, you can switch to a full on flowering base nutrient now. Ultra-premium two part nutrients may now be used, as they contain ingredients that are best applied to plants that re fully in flower.
* Increase your bloom booster concentration.
* Depending on how far along flower development is, you may choose to stop foliar feeding. Continue applying potassium silicate and plant immune system activators, but now at the roots.
* It is now okay to resume using B-Vitamin supplements at this time, if desired.
* Additions of beneficial fungi and bacteria are still recommended at this time to maintain plant health and to continue expanding the root system.
* Watch for nutrient build-up, and flush as necessary.
* If you have not already done so, begin to apply digestive enzymes to the rootzone to breakdown nutrient residues and any decaying root debris.

Week Four:

* Increase the concentration of your bloom booster in the nutrient solution. Bloom booster concentrations should reach their highest levels at this time.
* You may discontinue applying beneficial fungal and bacterial inoculants at this time, as colonies should be well established and there should be sufficient root mass.
* Nourish the beneficial bacteria and fungi in the rootzone with carbohydrates and humates
* Keep a close watch for any nutrient imbalances or deficiencies.
* This is typically a peak feeding phase for crops so change the reservoir often and water as frequently as necessary.

Week Five:

* Essentially, as above.

Week Six:

* Begin to decrease the overall concentration of nutrients. This includes bloom boosters as well as base nutrients.
* Advanced growers will switch from their early to mid stage bloom booster and may begin to apply their later phase/ripening bloom booster to the nutrient regimen.
* Increase your concentrations of digestive enzymes, carbohydrates and humates to keep the biology in the rootzone supercharged and functioning healthy.
* Increase your dosage rates of potassium silicate and plant immune system activators to help prevent any molds, mildews or rots from establishing on your crop.

Week Seven:

* Further decrease your overall base nutrient and bloom booster concentrations.
* Continue applying potassium silicate and plant immune system activators.
* Increase your application rates of digestive enzymes and carbohydrates.
* You may choose to retain your levels of humates applied.

Week Eight:

* Repeat week seven if necessary.
* If crop shows signs of ripening, begin to flush the growing medium.
* In hydroponics, use a high quality rinsing agent in the final phase to break the ionic bonds between the growing medium and fertilizer residues. Make sure that the solution drains freely away from the growing medium after applying the rinsing solution. Then proceed below as per “organics.”
* For 100 per cent organic crops, flushing isn’t necessary. However, you can omit all nutrients and apply only digestive enzymes and humates for the final week(s) before you harvest.
* If you flush for more than one week, it is a good idea to include potassium silicate and a plant immune system activator for the first few days in the flush phase to help prevent molds, mildew and rots from developing while flowers and fruits are ripening.

Week Nine:

* Repeat week eight if necessary.

The weekly breakdown is by no means a comprehensive guide, but it provides a basic overview of structuring a nutrient feeding program on a weekly crop phase basis. Overall feeding strengths will vary from garden to garden as dictated by the type of plant, environmental conditions, type of growing system, skill level of the grower, number of additives VS base nutrients and many other factors. However, as a rule of thumb, consider the following EC value system when deciding on your overall weekly feeding levels:

Invest in a high quality dissolved solids tester and pH measurement device. It will make you a better grower. A lot of crop problems can be prevented long before they start by carefully monitoring the pH and EC values of the nutrient being fed to the crops, as well as monitoring what drains away from the root system and growing medium. Using high quality measuring instruments allows you to accurately assess things such as when the crop is extracting the most nutrients from the medium and solution, when nutrient build-ups are occurring and when the solution or growing medium requires adjustment.

The wand-style EC meters are excellent because they are extremely accurate, simple and resilient (water-proof). A further benefit is that they can provide you with a read-out for EC, CF and TDS all at once. Different manufacturers sometimes use different ppm conversions. For example when a company in one part of the world says they are talking about 500 ppm and another says the same thing in a different part of the world, they could be slightly different values in terms of EC, for example 0.5 and 0.7 respectively. This is why it’s good to follow the manufacturer’s EC recommendations versus ppm. However, ppm (parts per million) is easy to work with too, just so long as you make sure you are using the correct ppm scale (check the specs. supplied with the unit).

For simplicity and an extremely high level of accuracy, you can use a combination all in one meter that has a probe for EC/PPM, pH and temperature. Remember that the quality of the probes and processors inside the unit will determine how accurate it is and for how long it will remain that way. Look for a unit that offers a high level of service and that can also supply you with the necessary cleaning and calibration solutions. Expect to pay more for higher quality units, but also expect to get a lot more for your investment.

The optimal pH range depends heavily on the type of growing medium you are using, and of course, the type of plant. Typically speaking the optimal pH range is from pH 5.0 to pH 6.0 in your nutrient solution to achieve a target pH in the growing medium. If your growing medium is more alkaline, you will run your pH on the lower end of the optimal range, conversely, you will run the pH of your solution a little higher with more acidic growing mediums to compensate, and create the perfect pH range for the absorption of nutrients.

Never underestimate the significance of EC and pH in the nutrient solution and what the levels are in the growing medium. Some nutrients and additives will drastically change the chemistry of your nutrient solution, while others do not; regardless of their effectiveness on crop production. So, it’s really important to know how each nutrient is reacting when you add it to your nutrient mix. Some innovative manufacturers are able to balance out their nutrient feeding programs so you are getting the optimal pH and EC level, provided that you are following their schedule to the letter and are using reverse osmosis or similar quality water to mix up your nutrient solution.

Intensive growers will want to explore the boundaries of crop feeding, and a high quality EC/TDS, pH and temperature meter is a necessary tool to navigate the nutritional demands of your intensive CPS endeavor.

Let us not overlook the significance of the plant’s other nutrient intake - the vital gas exchange required by the plant. Carbon and oxygen are very important nutrients, and must also be supplemented to achieve accelerated growth rates and super-sized yields. Roots require oxygen in the root zone, while the leaves take in CO2 from the air. Once lighting, temperature, humidity and nutrients are controlled and can be sustained in the optimal range, it’s time to boost your growth rates and yield by up to 30 per cent by supplementing CO2 to the leaves of the crop.

By safely increasing CO2 levels in the growing environment, the plants will grow at an accelerated rate, and will take up more water and nutrients than previously. There are several different types of carbon dioxide enrichment systems including:

* Chemical/biochemical reactions
* Compressed CO2
* Frozen CO2
* CO2 generator/burner

In small, well sealed growth spaces with minimal air exchanges required, compressed CO2 via tank and regulator or even bio-chemical reactions that give off CO2 as a by-product can be sued to boost carbon dioxide levels. Frozen CO2 (dry ice) works, but is usually not very practical, unless you happen to live next door to a fish packaging plant, because it melts fairly fast.

For most applications, either a CO2 tank, regulator and solenoid assembly or a gas fired CO2 generator will be required to produce sufficient CO2 levels in an intensive growing environment of any scale.

A timer can be used to approximate supplemental CO2 levels in the growing area, but is not nearly as effective or as recommended is as controlling CO2 levels with a high quality carbon dioxide monitoring device.

In our next installment we will have a more complete discussion of the ins and outs of supplementing the CPS environment with carbon dioxide to improve growth rates and yields. Because all the plants are in various stages, it is important that we take into account several factors that we will talk about to prevent problems and boost yields. You can also look forward to learning about the cutting edge in carbon dioxide generators and monitoring equipment, as well as what to look for when shopping for your own CO2 enrichment systems.

After we have our CO2 system in excellent operating order, we will have a final look at our CPS model and make some suggestions for improvements or areas worthy of further consideration or experimentation. So until then, make the investment and dial in you nutrient program to suit your growing style and weekly demands of your CPS crop to pack-on those gains you have been dreaming about. You spent the time to create the optimal environment, so make the most of it.

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Continuous Production Systems: Part 4
by Erik Biksa

Where we last left off, we began to discuss the benefits of supplementing carbon dioxide levels in our Continuous Production Systems (CPS) growth chamber model. We had a quick overview of some of the different types of CO2 enrichment systems and some choices with regards to the necessary components to put it all together. By supplementing carbon dioxide levels during vegetative growth, plants can gain more stature with an increased number of branches, leaves and potential flowering sites in less time. For the flowering area, increasing CO2 levels during the light cycle will help accelerate the flowering process creating bigger, heavier and denser harvests of flowers and fruits in a slightly faster time frame.

Remember that experienced growers only begin to take on supplemental carbon dioxide systems once the rest of the growing environment is totally dialed in and functioning smoothly. If you don’t have accurate and total control of temperature levels and lighting (as well as other growth parameters), the increased CO2 levels will be of limited value to the crop.

Thermal Reflector Covers - These made-to-measure thermal covers improve growroom cooling efficiencies; saving money and the environment.

As well, if your exhaust fans and intake, if applicable, are running frequently, most of the extra CO2 supplied to the plants will make it’s way out through the ventilation system before it has had sufficient contact time with the crop to be of significant benefit.

A key aspect of CPS is that in the flowering room, there will be several sets of plantings in different phases of flowering and maturity. Different stages in the flowering cycle would all benefit from different levels of carbon dioxide supplementation.

Of special consideration are ripening plants, which will produce higher quality harvest with better flavors, aromas, and other characteristics when CO2 levels are not elevated too highly. Ethylene is a hormone that is produced by the plant to help promote the ripening process. Ethylene production is inhibited by higher CO2 levels.

With the needs of all phases of flowering in mind, supplementing CO2 levels to between 800 to 1000 ppm (parts per million) as an average level in the flowering room will provide the necessary boost to keep flowering plants in overdrive without inhibiting the ripening process too greatly.

In order to facilitate a slight differential in CO2 levels between planting stages in the flowering area, note the placement of the water cooled CO2 generator in the area along with the placement of the probe that signals to the CO2 burner controller. The area further away from the generator and very importantly, the probe, should receive slightly lower CO2 levels than the area situated closer to the CO2 supply and monitor. The way you direct your air-flow away from the CO2 generator can further help to keep CO2 levels slightly higher in one area of the grow room versus others.

Some growers will wait until they have a few harvests under their belts before installing CO2 systems to help ensure they have the necessary budget available for the purchase of a high quality and accurate carbon dioxide monitoring and supplementation system. If you don’t invest in an accurate CO2 monitor/controller, you are only guessing and rolling the dice with how much CO2 is present for the crop at any given time.

The monitor/controller featured in this series of articles is extremely accurate, and of equal importance, it remains that way for a significant period. Most monitors use a single beam technology. As the filament of the infrared light that helps to calculate CO2 levels begins to wear out, single units will be giving less precise readings and, therefore, levels. The problem particularly becomes compounded over time. The dual beam units use an additional bulb to measure the light levels being emitted by the infrared filament that actually measures and controls CO2 levels. The second bulb measures and compensates for the diminishing light output of the bulb that does the “sniffing”. This way, CO2 levels and controls are much more accurate, especially over a period of time.

The unit is also relatively unique in that it accommodates a second optional probe, so one monitor can control two different CO2 generators or generator and tank combos completely independently, allowing for two zones of control in commercial sized CPS flowering rooms, or for independent CO2 control in a separate vegetative growth area. The probes use a CAT-5 network cable to connect to the controller, which can be kept outside of the growing area. The CAT-5 network cable can be extended for significant distances.

Most infrared CO2 monitors will require calibration every year or two to ensure accuracy. Some models you can calibrate yourself, but most require a shipment back to the manufacturer or your place of purchase to have the service performed.

For smaller installations bottled CO2 is a great option, because it is easy to install and relatively safe to use. However, even in smaller areas, the tanks will require frequent replacement; especially if not running sealed or “perfect” rooms where exhaust is infrequent or does not occur at all. For a lot of growers, gas fired CO2 generators are the way to go. They are available for propane (LP) or natural gas (NG). DO NOT hook up propane to a NG burner or natural gas to an LP burner or the results could be disastrous and potentially fatal! Having a gas fired CO2 generator requires a level of care and diligence. While in theory it is very similar to a BBQ, the fact that it is being used in an indoor environment requires very careful consideration and care.

For safety, never bring a propane tank directly into the growing area, or even inside the building. Long hoses are available for propane tanks, so keep them outside, and carefully run the hose to the generator inside of the growing area. Carefully inspect the hose and any connections for leaks with a solution of soapy water. NEVER use a damaged tank, supply hose or regulator; you are literally playing with fire. If you have a natural gas supply, have a qualified technician install a hose/supply with an on/off valve that meets or exceeds your local code.

Make sure the CO2 generator is securely mounted (chains and hooks are great) and the CO2 distribution openings are several feet away from ceilings. And always make sure that there is no possibility that the burner can come into contact with any flammable materials. Areas that are prone to earthquakes may require special considerations.
For the ultimate in safety and high efficiency CO2 generation, look for water cooled CO2 generators, such as the unit featured in this series of articles. The unit is compact and runs so cool that it can be safely wall mounted, provided that it is a safe distance from ceilings. This is excellent, because it keeps the unit out of harms way, and there is much less of a chance of whacking your head on it as you intently observe your garden.

Remember, maximize the amount of usable space in your growing area, as you will get bigger yields and make the most of your expenses associated with the inputs required per square foot of area.

Most gas fired CO2 burners produce a lot of heat while generating CO2. This heat winds up in the growing area. In an in/out situation, the exhaust system will be activated, defeating the CO2 supplementation. In sealed or “perfect” rooms it will cause the air-conditioning system to cycle more frequently, increasing your electrical consumption. Water cooled units use a heat exchanger in the combustion area of the unit that captures the heat in the water supplied to it. Here it is drained away to waste for cooling, or for other purposes. In this way, most of the heat is captured and never enters the growing area at all. Even at the maximum CO2 output, which is a big 45 cubic feet, you can hold your hand over the discharge. Try this with a conventional model, and you might be on a trip for medical attention.

The output of the water cooled CO2 generator is totally controllable from 15 to 45 cubic feet, so it can be adapted to just about any sized growing area. Some of the safety features include a tip-over shut off, low flow shut off and the use of electronic ignition, so there is no standing pilot light.

For the greenhouse grower or indoor grower in cold climates, the heat that the unit captures is a dream come true. The water heated and captured during the light cycle can be circulated through hydronic heaters in the growing area or directly in the root zone to radiate warm heat during the dark cycle, when temperatures may need to be supplemented to stay optimal for growth or flowering. It could also be used to reduce the heating costs of residences or institutions in cooler climates.

The CPS model featured in this series of articles demonstrates an in/out ventilation/cooling system with air-cooled lighting for temperature control. It is very reliable and extremely accurate when using the automatic day/night centrifugal fan speed controller featured. However, in hot climates, it may not be enough to keep the temperature between 72 to 82°F in the flowering area (directly under the lights). It also restricts the capabilities of the CO2 enrichment system, because the CO2 generator is defeated by the activation of the exhaust. This is accomplished by a special controller that uses a relay system to de-activate the CO2 burner when the exhaust fan is cycled. Otherwise, a lot of the CO2 generated would just be wasted.

To further improve the CPS model, a closed loop or sealed room can be created. Instead of using exhaust fans and intakes, an air-conditioner will do a lot of the cooling. The heat from the AC unit still needs to be discharged away. Most AC units blow the heat away, which can be ducted away from the growing area or water cooled air-conditioners can capture any heat and drain it away very efficiently (although they require a significant volume of water to operate; typically a minimum of 1.5 GPMs).

As humidity will no longer be exhausted, a de-humidifier will be necessary, although the AC will help to reduce humidity levels while it cycles. A carbon-scrubber should run 24/7 to help keep the air clean and reduce the possibility of plant diseases or other disorders, as well as ensuring that the air remains smelling fresh and clean. With the existing CPS model featured in this series, very few modifications to the growing area would be required to make the switch.

To reduce power consumption from the AC cycling frequently, the air-cooled lighting and thermostatic fan speed controller could remain installed, removing a lot of the heat from the grow lights before it ever enters the growing area. To improve the efficiency of air-cooled lighting, specially fabricated and fitted thermal wrapping is available for air-cooling ductwork, reflectors and fans. The fabric-like material fits perfectly over these items. FLIR (forward looking infrared) guns have shown that the heat inside the ductwork, reflectors and fans does not escape into the growing area, helping to further reduce the cooling requirements of the growing area and, therefore, the overall efficiency of the CPS endeavor.

If you wish to eliminate the discharge of air from your air-cooled lighting, there are special water cooled heat exchangers that can be used in line with your air cooled lighting system, which simply circulates within the growing area (no outside intake or exhaust). As long as the water going to the in line ducting heat exchanger is around 65°F, the air in the grow room will not heat up as quickly, reducing the cycling frequency of energy hungry air-conditioners. While air-conditioners work great to keep CPS installations cool, they use an awful lot of energy, relative to the amount of cooling they perform. Water cooled in line heat exchangers in the modified “open” air cooled lighting system can keep things cool for a fraction of the energy required versus an AC unit by simply using a ¼ HP water chiller (as used with hydroponic reservoirs). The chiller unit will draw less than 250 watts on average, and helps you to keep your cooling water at 65°F or less, depending on the set point.

However, for the ultimate in CPS, look to water cooled lighting. As featured in the Urban CEA series of articles, there are a lot of benefits. Firstly, liquid cooling is a much more efficient process versus air cooling. Whether a super-bike or performance car, chances are it’s water-cooled.

Water cooled lighting allows for the closest plant to lamp tolerances possible. Sure, some of the light gets lost through the water, but the grower can provide incredibly high light levels to the plants, as the water cooled units run cool enough to allow the placement of 1000 watt HID lamps within inches of the plants, if required. They also help to create a very quiet growing environment. Air-cooling can be quite noisy, even with some of the grow room construction secrets revealed through this series of articles.

In this model, the following areas can be adopted to water cooling for high efficiency, optimal grow room temperatures and crop performance:

* CO2 burner
* Water cooled lights
* Hydroponic reservoirs
* Air Conditioners
* Air cooled lighting with in line heat exchanger (converted to a modified “open” system)



All of these items, excluding the water cooled AC, can be connected to the same water tank and cooling system, although a very large volume of reserved water would be recommended if connecting a water cooled CO2 burner to the same water cooling system as the lights. Above ground swimming pools are inexpensive, or existing swimming pools or other bodies of water can be used.

One of the great things about the water cooled lighting system featured in this article is that it is suitable for vertical installation. In the earlier phases, when plants are smaller and branching should be encouraged, containerized plants can be huddled around the vertically mounted unit. With the extremely close plant to lamp tolerances, and the fact that the light is being delivered to the sides of the plant (which should be rotated daily or at least every few days), early flowering growth is squat and bushy, with many branches maintaining tight internodal distances for heavier yields.

Another benefit to vertically installed water cooled lighting for early flowering is that when plants are smaller there is little canopy to shade the growing medium. Until the canopy is developed, the growing medium can heat up quickly when exposed to direct and intense light; that is unless it’s water cooled lighting. Overly warm growing mediums are prone to root diseases and other disorders, significantly reducing the yield potential of the crop.

As a final note in the area of Continuous Production Systems (CPS), be prepared to practice a high degree of grow room sanitation. Because CPS always involves maintaining a number of plants in different phases of flowering/reproductive growth in the same room, diseases and insects can be extremely hard to get rid of if they surface. The CPS grower cannot “A-Bomb” there room between crops, as the grow room always contains flowering plants. Neem based products can be applied to plants as dunks or sprays before any plants ever enter the flowering area as a preventative and control measure, and re-applied three weeks later.

Foliar applications of products that contain silicate and products that contain plant immune system activators will help keep your crop free of foliar diseases. Combine products that contain highly pure potassium silicate with products that contain chitin and salicylic acid into the correct dilution rates and adjust the pH to 5.0 after adding a non-ionic surfactant. It will stiffen stems, for heavier fruit loads while making your plants very hardy and capable of resisting and preventing diseases that cost yields. As the flowers or fruits begin to develop and spraying becomes undesirable, apply these products as a weekly or bi-weekly treatment at the root zone. When you begin to consistently harvest disease free plants, you will thank yourself for having bulked-up your plants with these beneficial substances.

Inoculating the crop with biological treatments of beneficial fungi, bacteria and protozoa will further help improve the crop’s resistance to diseases and insects while promoting bigger and healthier root systems. For the 100 per cent organic or hydro-organic grower, biologicals are counted on for the conversion of organic matter in organic nutrients and the growing medium to plant available nutrients, naturally occurring growth hormones and amino acids.

A microbial tea brewer (featured) and cartridges allow growers to brew teas for plants that are consistently high in both populations and diversity of beneficial microbes. Each batch produces either five or 10 gallons of bioactive tea that will retain a healthy vitality for up to seven days when refrigerated. A five gallon brew will treat up to 250 gallons of solution, so unless you are gardening on grander scales, it’s probably more convenient to use a pre-brewed solution. To avoid the limitations of shorter shelf lives, you can use powdered or liquid suspensions of dormant microbial concentrates. Note that the brewing process helps to multiply the microbes very quickly, versus just adding to your reservoir. Apparently, in a 24 hour brew period, the microbes can multiply up to eight billion times!

Prepared bio-inoculants are economical, consistent and highly effective. Most are available in powdered forms with separate bacterial and fungal blends that can be combined. The operator of one CPS model noted that the effects of the freshly brewed nutrient/microbial tea were enhanced with a follow-up application of blended powdered bio-inoculants.

Starting each plant that ever enters the growing area from seed is the best way to ensure a pest and disease free CPS model. Although seeds take longer to reach maturation versus starting from cuttings, the flexibility of CPS with regards to when batches of seeds are started, transplanted, vegetated and subsequently flowered will really have no impact; you can still harvest every 10 to 14 days, or as frequently as you plan with your own CPS cropping schedule, even from seed. All you need to know is how long it takes for a germinated seed to reach a size that can be transplanted for vegetative growth, how long it takes in vegetative growth to reach the desired size for flowering and naturally, how long it takes to flower to maturity. From there you can start to dissect the times in each of these areas, and build your own CPS cropping model.

If acquiring cuttings from outside sources, you can also be acquiring problems. Do not introduce problems into a healthy growing endeavor; it will set you back and cost you yields, time and grief.

The possibilities with Continuous Production Systems (CPS) are virtually limitless; these principles and practices can be applied on any scale whether you are a two light hobbyist or a 100 light grand master grower. At first you may stumble, but once you have refined a CPS schedule to your favorite strain(s) and begin to harvest as frequently as you can handle, the rewards will become clear. Perhaps at a later date, we will step back into the CPS model and share further refinements, successes and errors. Until then, you are only limited by your imagination and the amount of time you put into the endeavor. Growers are encouraged to report their experiences with CPS models with the author so that they may be broadcast with loyal readership and others that contribute to the refinement of the continuum in the Continuous Production Systems we create.

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