The first generation turn-key marijuana grow systems were the original phototron systems which were highly popular in the early 90s and capable of growing a single plan in a soil medium. Since then turn-key marijuana grow boxes have come a quite long way. Today these systems are no longer just for small stash growing. They are totally capable of producing potent, high yielding cannabis crops. The technology that goes into these systems have increased substantially and the prices have remained low to the point where these systems can pay for themselves after one or two harvests.
Some systems today come complete with miniature hydroponic systems, high-intensity discharge (HID) lamps and even feature CO2 injector kits and air filtration systems. With better technology and cheaper material costs, more and more manufacturers are finding ways to fit everything a complete grow op would need into smaller packages that make for much better use of space and resources.
These new systems are made to fit snugly into closets or disguised to look like mini-refrigerators, storage cabinets, utility sheds, and even computer cases. They can be used hydroponically, aeroponically, or with soil. Some systems have completely automated controls for atmosphere, lighting and feeding systems and most can be modified to customer specifications before ordering—or amended by growers themselves after-market.
A good turn-key marijuana growing chamber can cost as much as $4000-5000, so for some people it makes more sense to construct their own system rather than buy one and have to wait for several harvests before being profitable.
Some popular turn-key systems out there:
Cool Cab - $1800.00
Mini Cool Cab - $1200.00
PC Planter - $450.00
AeroGarden - $129.00
Building Your Own
One of the first things you need to think about before starting out and collecting the parts you need is how much bud will you need, and how often? Will you to be growing for personal use or to sell, or both? Are you just growing as an experiment and don’t yet plan on being self-sufficient?
Most marijuana plants finish in around 8-12 weeks depending on the strain and the growing method used. The veg period can be anywhere from 2-6 weeks. You can increase your productivity by having a veg growth box which is seperate from the actual flowering chamber. Using this method you can veg the plants right up to when they are ready to flower and then put them into the flower box on a 12/12 light/dark timer method or you can have 2-4 plants per foot SOG style and veg for only two weeks.
Smaller cabinet systems usually use lights within the 70-250w range. Closet systems usually use lights within the 400-600w range. Grow room systems usually utilize lights within the 600-1000w range. In Sonoma County it is legal for anyone with a medicinal marijuana prescription to grow up to 30 plants within a 10×10 area. However in some areas it is illegal to grow so you need to only use a reasonable amount of energy in relation to your typical usage to avoid raising a red flag with the power company. If you have a +2200 sq ft house you may not want to exceed 3000 watts total. With a 1000 sq ft apartment you may want to stick within the 250-600 w range. You need to ask yourself what is realistic. Some people go as far as using propane tanks hooked up to generators to put their system completely off the electrical grid.
The first thing you need to do is get power into the box, most people use a power strip like below, they are good enough for most systems up to around 250w, with any more then 250w then you should run solid copper wires and have GFI outlets and have the grow have its own breaker.
Fluorescent lights are the cheapest light to use. They run at about $2 a tube. They produce little heat so ventilation may not be needed unless the space is very small. The light spectrum put out by these lights is suitable for all stages of growing. Because fluorescents disperse light over a large area, they need to be kept within three inches of the tops for the plants to receive enough light. This means you will have to mount the lights in a way that the can be raised everyday.
Metal Halide Lights
Metal halide lamps put out the most light. They also produce a lot of heat. A strong fan is needed to keep room temperatures down. MH lamps put out light mostly in the blue spectrum. Blue light is used best by the plant during vegetative growth. MH lights can also be used for flowering with no adverse effects. A separate ballast is required for these lights to work. They come in sizes from 40 to 1000W. One 1000W lamp will provide enough light in a closet to grow four plants.
High Pressure Sodium Lights
High pressure sodium lamps put out almost as much light as MH and with less heat. Good ventilation is still required though. HPS lamps produce light in mostly the red and orange end of the spectrum. The plants uses this light best when flowering. HPS lamps can also be used for vegetative growth with little slow down in foliage production. HPS lamps require a separate ballast for operation.
Some growers switch between MH and HPS depending on what stage the plants are in. MH is used in vegetative growth and then the light is switched over to HPS once flowering begins. Most growers use fluorescents to start seedlings and root clones. The fluorescents are weaker than the MH and HPS lamps and therefore do not stress them too much. Choose whatever light is best suited for your situation. If your are growing in your attic go with MH or HPS. If your growing in the closet like us, then use flourecents.
Ventilation and Air Flow
Ventilation is extremely important within your growing space. If you do not have enough ventilation and the box gets hot you will use up all the Carbon Dioxide causing you to dramatically lose crop yield due to inadequate cooling and air circulation. You will definitely need both an exhaust fan in any grow system.
Marijuana like all other plants puts out waste through the stomata on it’s leaves. Outdoors wind, rain and sun are present to evaporate these toxins from the leaf surface. Indoors the grower must create an environment. The best way to do this is with a fan of some kind. If the grow room is large enough then an regular cooling fan can be placed inside and left on all the time. If you are running a small closet operation then just opening the door twice a day to look at them will create enough air movement for healthy growth. A fan controlled by a thermostat will also work well. These can be found at most electronics stores.
If a large number of plants are to be kept a dehumidifier may be needed. If humidity levels are too high then the chances of mold will dramatically increase. A dehumidifier will cost a grower about $100 so it isn,t really practical for the closet grower.
Fan placement is totally key. Heat rises so you want the exhaust fan blowing the hot air out the top of the box and the inlet holes at the bottom. You do not need an intake and exhaust fan because if you just have an exhaust fan blowing out you create negative pressure and this will suck from the inlet holes and any other gaps you have. This is great because the smell will be contained as long as you have a carbon filter placed after the exhaust fan. The inlet holes should be at least the size on the fans, optimally around 2x the size. The bigger and smother the air inlets the quieter the air movement will be, so radius the inlet edges. A PVC elbow works great as a light trap, just paint the inside black so light doesn’t bounce though it and emit a glow out the end.
You want to evenly distribute the air across the grow box for even growth. A circulation fan in the box blowing across the buds is a good idea. It also cools the buds and increases growth and yield.
Some of the easiest fans to use are computer fans because they are quiet and reliable and cheap at around $4-$15 each. Opt for the ball bearing fans because they last longer, are quieter, and don’t go bad and get extremely loud like bushing fans. One 80mm fan is good enough to cool a 70w HPS, or floros around the same wattage. 2-3 fans would work well for a 150-250w HPS. To power the fans which run on 12v dc use an AC/DC adapter or a computer power supply. If your doing a stealth setup you want a 9V charger so the fans will run slower and quieter, or you can buy a 12v and use a dimmer to make your fans run more quitely.
The adapters rating is in milli amps and the fans rating is in amps, so to convert move the decimal over 3x, so 600ma=.6a . You want to keep the power supply rating higher then the fan draw, otherwise your run the risk of overheating the charger and it failing on you, or making a fire.
If your using a carbon filter with a 150w+ watts you may want to buy a centrifugal blower like a Dayton Blower.
They push the air with more pressure so are much better for pushing through filters, look on ebay for a used one that will fit your application. The Dayton blowers are a bit noisy but you can muffle and dampen the noise by hooking it up to a light dimmer and have the fan on some kind of dampening material. Always put the carbon filter after the fan with centrifugal fans. Listen to the fans inlet when it’s on and if the airflow surges (sounds like a quiet helicopter) instead of the sound being constant, the outlet of the fan it too restricted. That can either mean the carbon filter is too restricted or the pipes are too small.
Placement of the fans is key for noise. If you place a fan the center of a wall or ceiling the fan will shake the panel and make your grow box into a big drum increasing the noise. Place the fans in corners where the structure is stronger and less likely to vibrate.
Grow box sizing should stay in the 45-70 w/ft with soil and but you can grow with 75-90 w/ft if you need or want. But unless if you hydro with co2 enrichment or allot of airflow the plants wont be able to use all the light you give them efficiently because they are limited by the amount of nutrients and co2 the plants can absorb. If your growing a stadium style setup or U-ScrOG you can have higher w/ft because the effective w/ft is lower because of the increase in canopy area and absorbs more of the light.
To calculate how many w/ft in a given space use the following equation: watts/ (depth x width)
Now that you have an idea on the dimensions, lights, and fans you need to find or make a box. The minimum height is around 28” inside height for growing small 70w ScrOG, you can grow shorter by having a lower screen and less soil but the lower screen increases the chances of snapping a branch and less soil can lead to root bound or medium that dries out too fast.
If you plan on growing more then one harvest your far better off having a veg box for female plants and cloning. The benefits of cloning are you know the plants a female and you can flower anytime because it’s a mature plant. I would never, ever use seeds for growing with all the available clones out there at the dispensaries. Using clones means that all your plants are guaranteed to be female, no seeds ever, and they are usually more potent, higher yielding strains that have been generically engineered and evolved to produce higher amounts of quality bud.
So I would either integrate a small veg box with either a small 30-50w MH, some daylight CFL’s or 1-2’ floro tubes in a mix of warm, cool and or daylight floro tubes. With veg you only need around 25-40 w/ft of MH, cool, or daylight to keep the plants short. And the veg box only needs to be around1’ high min and as narrow as 6-8”. The warm bulbs will help growth but without the blue spectrum the plants will stretch.
The light and fan timers are externally located on the outside of the grow box, and are the heavy-duty models for higher wattage. The top timer is for the 400 watt high-pressure metal-halide bulb and fan in the larger upper chamber of the box - used for vegetative growth and flowering. One fan stays on all the time. The bottom timer is for the lower chamber’s flourescent fixtures and lower air circulation fan (optional).
It’s important to maintain a relatively constant temperature in the growing unit. Fluctuations of a few degrees are ok, but wide variations in temperature can produce less dense and compact plants. For temperature control, I monitor using a min-max type thermometer, as well as 2 standard thermometers, one in each chamber. For ph levels, I use a metered probe type unit. Here you can also see a small air circulation fan and standard thermometer.
Marijuana can survive temperatures from 32 degrees F to over 100 degrees F. Cannabis will grow best with a temperature of 70 to 75 degrees F day and night. Higher than 90 degrees F the enzymes within the plant begin to breakdown and photosynthesis is affected. The same is true for low temperatures.
The humidity in the environment is the amount of water vapor present in the air. Most growers know that humidity in excess of 85% percent increases the probability of the appearance of bud mold. The humidity is also critical during germination when the seedlings are extremely fragile. Humidity should be kept over 80% at this stage in the plants life to prevent the soil from drying too fast. Experimentation has shown that a relative humidity of 65% to 80% increases growth rate. Below this level the plants develop extremely narrow and tissue paper thin leaves to try to prevent excess loss of water. Above 80% relative humidity the plant have trouble disposing of toxic chemicals through evaporation.
Carbon dioxide is a gas that is essential for the light reactions in all plants that carry on photosynthesis. CO2 is absorbed through the leafs stomates and is combined with water and light energy to form glucose (used by the plant as energy) and oxygen (which is released). Therefore supplementing CO2 to the existing amount in the air will speed up photosynthesis and therefore, growth will occur faster. Experimentation has also shown that CO2 can help marijuana tolerate higher temperatures (up to 95 degrees F) with little affect on the rate of photosynthesis.
Although only a small portion of water absorbed by the plant is used in photosynthesis a shortage of water does affect the rate photosynthesis occurs. This happens because when the plant is low on water the stomates on the leaves close preventing the release of waste gases and other toxic chemicals. This closure will severely slow down or even stop photosynthesis from occurring.
Sea of Green
Sea of green, or SOG, is the theory of harvesting many small plants frequently, instead of large plants less frequently. In an SOG setup the closet is divided into two light tight spaces. In the top space the lights are permanently set on a 12/12 light/dark timer. On the bottom the lights are kept on for 18 hours per day. fluorescent lights are used throughout. The bottom shelf is used to start seedlings and root clones. The top shelf is used for flowering. Using this setup harvesting can take place once a month.
All wiring is professionally installed and plastic wire clamps attach all wires keeping them securely in place and out of the way. The 400 watt ballast and capacitor sits on a 3/4 inch plywood shelf, on a piece of fireproof drywall in the upper part of the grow box. The ballast area is also vented for cooling. I use adjustable chains to raise and lower the lights. It’s worth the extra effort to ensure all wiring is secure and lighting is properly mounted.
Paint the walls flat white. Do not use tin foil because it can actually focus light like little laser beams and burn holes through the leaves. Next, cover the floor with plastic. This will help stop water damage to the floor.
Some growers add C02 to their grow rooms to increase growth rate. This has proved itself to be effective in many experiments. C02 supplementation also helps the plants withistand higher temperatures of up to 95 degrees without slowing down growth. There have been complaints however, that C02 supplementation during flowering reduces potency. Therefore, C02 should be stopped when the lights are turned to 12/12.
Harvesting and Drying
When you want you plants to start flowering just turn the lights down to 12 hours light and 12 hours dark. Then be patient and wait for flowering to complete. It helps the drying process a little if you don’t water the week before harvesting. When you cut the plants remove the large fan leaves the and add them to your compost pile as they are not usable for smoking. Place the plants in shoe boxes or paper bags and stir them around daily. In about three weeks the buds should be totally dry and ready to smoke.
Simple Marijuana Grow System
Intermediate Marijuana Grow System
Advanced Marijuana Grow System