How To Build Your Own Cannabis Grow Room
So, you have decided to grow your own cannabis at home. Nice one! Growing your own cannabis not only guarantees a continuous supply of wonderful weed, it also leads to a greater appreciation of the herb and the sense of a job well done. It is well documented that time in the garden is as beneficial as meditating, increasing one’s sense of well-being and even helping combat anxiety and depression.
Growing cannabis at home means having somewhere dedicated to growing. To produce enough weed to last from harvest to harvest, a minimum of 1m² is recommended. This will accommodate a number of smaller plants or one or two well-trained, or even scrogged, larger plants. All this is up to you; the yields in the end are similar, it just depends on whether you want a lot of variety with smaller yields per plant, or less variety and larger yields per plant. It is entirely up to the individual.
The height of the grow room is dictated by available space and lights being used. A single square metre is easily covered by most styles of grow light. Less height is required when using fluorescents, as lights can be kept closer to plants throughout the grow, whereas HID lights need more distance to avoid light burn and excessive heat buildup. You might want to blast your babies with a 1000W HID, but without appropriate height, this just isn’t possible.
SELECTING A SPACE
Everyone can find an easily accessible spare square metre somewhere in their home or apartment. Spare rooms, attics, basements, cupboards, and walk-in robes can be used to set up a grow space. Discretion is a key factor; fan noise, light buzz, and odour control each need to be considered when selecting a space to set up a grow room. An oscillating fan attached to a shared partition wall, for example, will drive your neighbours crazy with the noise and sympathetic vibrations.
An entirely light-proof grow room is absolutely necessary. In the first instance, light leakage can be annoying because grow lights are extremely bright. Light leakage can keep you awake at night if your grow room is a bedroom cupboard or set up in a spare corner of any inhabited room. At worst, it will advertise that you are growing weed to your whole neighbourhood.
Secondly, light leakage into the grow room can adversely affect plant performance. Once plants have been flipped to the 12-12 day/night cycle to induce flowering, light leakage can confuse plants and lead to a lower yield, hermaphroditism, or even failed crops due to light stress. All growers keep a keen eye out for male plants, but missing a few well-hidden bananas on females can ruin a whole crop by sending it into seed production.
Once your grow space is set up, do a test by turning on the lights and inspecting for any light leakage. Any cracks or holes that let light out will certainly let light in. When and if discovered, patch the holes with light-proof tape available at hardware stores or with at least two layers of gaffer tape—gaffer tape is semi-translucent, even the black stuff, so just one layer won’t do the job.
Most electrical equipment kept in a grow room, such as dehumidifiers, have quite bright micro-LED lights, which can do the same plant damage as environmental light leakage. Place a piece of tape over any lights on these types of appliances to ensure nights are the darkest of dark. Outdoors, the subdued light of the full moon has beneficial effects on plant growth, but this effect is difficult to translate to an indoor grow.
As it matures into resinous, fat buds, good cannabis smells—it’s as simple as that. Some weed even overpoweringly reeks and can stink out a whole room, a whole house, or even a street. It is easy to become used to that luscious aroma when visiting your plants often, and become convinced that the smell isn’t going further than your grow room—but nothing is further from the truth. A well-sealed grow room prevents aromas from disturbing neighbours or your fellow inhabitants.
A well-sealed grow room also makes climate control easier to maintain. Temperature control and dehumidifying/humidifying air rely on a sealed environment without any drafts. A stable environment is very important for optimum plant performance. A well-sealed room also acts as a quarantine cell for your plants, preventing any bugs, vermin, or airborne pathogens from entering. A single mouse can do a lot of damage to cannabis in only one night, especially to young plants, as they are voracious for nutrient-dense cotyledons and young stalks.
It should be noted that an airtight grow room is a low-budget solution. Spending more to set up an air exchange system will benefit your weed substantially and will pay itself back in the long run. However, airtight grow rooms are the ideal environments for experimenting with CO₂ enrichment for added plant performance.
Healthy cannabis requires moving air. Any grow room will require at least one oscillating fan to ensure air is continually in circulation. Moving air has a number of benefits for the cannabis plant.
At a minimum, moving air should ruffle all the leaves on a plant to ensure fresh air is available to the leaf stomata. In still environments, stale air can build up on the undersides of leaves around the stomata and hinder efficient gas exchange. This has the undesirable effect of inhibiting plant growth; stems will become weak, leaves will droop, and plant performance will be poor.
Moving air strengthens plants considerably; stems and stalks become thicker and more robust, and end yields will be higher.
Moving air also helps with the wet-dry cycle of the growing medium by supporting evaporation. Moreover, it prevents pathogens caused by moisture buildup on leaves as they transpire. Moulds like nothing more than a moist, warm environment.
With a higher budget, introducing an air exchange system stimulates better growth. Air exchange requires an inlet for fresh air and an exhaust for depleted air. With a higher budget still, incorporating a carbon filter into the exhaust system will keep the stink factor to a minimum.
Air inlets are passive and can take a number of forms; however, they are always situated in the lower part of the grow room, either in the floor if the floor is raised, or in a wall. The main consideration is light control when putting perforations into a grow room. A simple slot, vent, or series of holes will provide ample air intake, but can be indiscreet with light. Using a piece of ducting with a bend in it, or configuring a double wall arrangement, stops light escape. The easiest thing to remember is that light can’t go around corners, so introducing an arrangement with a bend of some kind keeps your grow discreet. Also, provide some kind of vermin barrier to dissuade any critters that want to get in and feed on your precious weed.
An air inlet means there will also be an air outlet or exhaust system, ideally with a carbon filter attached. Exhaust systems remove depleted air and heat from the grow room and draw fresh air in. Where possible, it is desirable to exhaust to the outdoors to prevent heat buildup in closed spaces, or to recirculate the same air back into the system. This can often be a challenge, but ducting is your friend when solving air distribution problems.
The capacity of an exhaust fan is dictated by the volume of the grow room. Length × width × height will give the volume of the grow room, and the manufacturer will recommend what fan will be right for the job. It is recommended to go up a size to ensure proper air exchange, and to accommodate any potential increase in the scale of your grow.
Cannabis thrives when the climate is controlled in regard to humidity and temperature, with certain parameters ideal for vegetation and other parameters ideal for bloom.
Humidity can be easily controlled with a dehumidifier; these are also available as double-action units that will add or subtract humidity as necessary. During vegetation, a humid and warm environment increases the rate of growth, while lower humidity and temperatures increase bud development.
Temperatures can be controlled with small, portable, reverse cycle AC units. Many humidity-modifying units and heaters come with built-in thermostats and hygrometers, so they switch on and off as the environment demands. Just set them, and rest assured your weed is booming at every stage; automating the whole thing makes growing life a lot easier.
SAFETY AND FIRE PREVENTION
Although most growers make it to harvest time without any mishaps, numerous horror stories document how bad things can get when an accident happens.
Although many cannabis growers like to keep their operation minimal, others like to use as many helpful gadgets as possible. But, even a small number of electronics in the grow space runs the risk of fire.
Water remains one of the biggest risks in the grow room when it comes to electronics. Water can interrupt an electrical current, potentially leading to a fire or electrocution. Try as hard as possible to keep electronics elevated above the ground in case of any water leaks.
Place a fan in your grow room to regulate temperature. Although this means even more electronics floating about, a fan will create a cool air current and help to prevent devices from overheating.
Using a ground fault circuit interrupter (GFCI) will help to stop electrical leaks when they arise. This piece of kit detects when electricity flows where it shouldn’t—in a pool of water or a human body— and breaks the circuit.
Keep your grow room as tidy as possible. Create a dedicated space for each piece of equipment, and keep wires running neatly using plastic zip ties. If you notice any damaged or exposed wires, repair them immediately.
Clear away all tools after using them to prevent any trip hazards. Keep your pruning shears, watering cans, and spray bottles packed away in a toolbox when not in use. Not only can tripping result in injury, but you might also land on your plants and cause some serious damage.
Although rare, you should be entirely prepared for a fire to break out. Grow room fires can destroy your property, put your life at risk, and also expose your herbal hobby to the authorities. Keep a fire extinguisher close by at all times in case your setup goes up in flames.
Instal a fire alarm in your grow room to alert you if a fire breaks out. Purchase a handheld fire extinguisher and keep it at the entrance to your grow room or tent. Purchase a model that contains dry chemical powder or CO₂ suitable to tackle electrical fires. Alternatively, purchase an extinguisher ball and position it above your growing space. Upon exposure to excess heat, these devices explode and release fire-retardant powder.
Now that you have selected a space that satisfies the demands for a healthy and discreet grow, it’s time to actually build your grow room. There are a number of solutions to create a grow room at home on a budget. This method uses a number of plastic-lined wooden frames to form the walls, base, ceiling, and door. When including a ceiling, supports for the grow lights will need to be incorporated. When dealing with existing walls and ceilings, BE ABSOLUTELY CERTAIN OF THE LOCATION OF ELECTRICAL WIRING. Also, tenants will need to consider the future repair of any surfaces that might be affected when building their grow room.
What you will need:
• A saw
• A stapler that can staple to wood
• Doubled-sided plastic sheet: one side black, the other side white or reflective like Mylar
• 4 small hinges
• A drill with a drill bit and a screwdriver bit
• 26 angle plates
• Plastic corner protectors (optional)
• Timber to suit: 4x4cm (or close enough) pine or similar softwood is easy to handle, strong enough, and cheap; your local hardware shop will certainly have this available in a variety of lengths
1. To create the top and bottom of your frame, you will require 4x 1.0m + 5x 92cm laths of wood.
– To create the sides of your frame, you will need 7x 192cm laths.
– To create the door, you will need 2x 1.0m laths + 2x 192cm laths.
2. For the top: To affix the laths, drill holes 2cm from each end, and one in the middle for the spax. Do the same to the bottom. For the door: Drill holes 2cm from each end in the 1m laths. Spax together with the vertical beams.
3. Now that you have created the bottom frame, take one of the 192cm laths, place it in one corner, and affix it with two angle plates. Repeat in each corner.
4. Now that all 4 are in place, place the top and affix all vertical laths to it with angle plates.
5. Measure out the middle between the vertical laths and affix your stabilising beams with 2 angle plates (3 for where they meet the supportive beam of the top frame).
6. Using scissors, cut a piece of plastic/Mylar that will overlap every edge of each frame. Staple the plastic into place on the overlapping edge using plastic corner protectors.
7. Locate the door and screw the 4 hinges into place.
8. Voila, your grow room is now ready to be fitted out.
For a start, we need to ensure that the space is made completely light-proof. In order to bloom to its peak the cannabis plant needs 12 hours of undisturbed night and 12 hours light.
Which Room in the House is Best for Growing Weed?
by Sammy Spade (with contributions by Nebula Haze)
A lot of new growers rush into setting up their indoor garden without a proper plan. And dare I blame you? As an exciting new chapter in your life with great rewards, you’re anxious to get started… but it’s also an endeavor rife with challenges. Challenges you need to take very seriously.
Deciding which room of your house to use for producing home-grown weed presents a complex problem, and reserving some meaningful consideration goes a long way towards making your job easier and your grow a more successful endeavor.
Would you launch a business without a plan? Probably not. Or perhaps your answer is yes. Perhaps you would start a business by just moving forward and winging it as you went along.
Fair enough, so would I, to be completely honest with you. But even so, I strongly encourage a methodical process for setting up your grow. Although it’s possible to wing it with growing cannabis, there is so much at stake and so much room for failure that the importance of a plan is crucial to saving you a lot of time and more importantly money!
Let’s look at some of the different aspects you want to take into account before choosing a room to try out your green thumb.
7 Guiding Principles To Creating the Perfect Grow Room
A smart grower puts a lot of effort into concealing their grow from the public. Even if you are growing medical marijuana and have gone through all the motions demanded of a legal pot farmer (and I still highly encourage you to do so), you don’t want the whole world knowing what you are up to.
Even though you can run a legitimate operation these days, headaches are no less real if the authorities decide to give you a little trouble, even if just to make you uncomfortable. On top of that, you face a real danger from burglars, many of who are armed and dangerous.
So, secrecy is paramount.
Look at the different rooms in your house and consider how easy their location will make it to hide your grow once it’s set up. If growing inside, will guests notice something fishy going on, or can you just keep them away from the door to the room and call it good?
A stand-alone room separated from the main house is a stealthy location for minimizing damages and keeping it away from guests (dogs loose in the yard serve as a fantastic burglar deterrent), but how will you keep light from spilling out the door every time you enter the room during the “day cycle?”
2. The Exhaust System
Your exhaust system creates another challenge. With any powerful grow light (even LEDs start getting hot once you get to the larger models that pull more than 250W of power out the wall), your room will surely need a nice system that pulls out hot, stale air and replenishes the garden with cool, fresh air.
A common option (this is what I do and probably what most hobbyist growers do) is to vent heat out a window using a fan plus ducting to suck air out of your grow space. The main challenge with this is making sure that your window still looks normal from the outside so no one can tell you’re using it as a vent. There are several ideas on how to do this!
If you can’t vent out a window for whatever reason, there are possible solutions for building your exhaust system directly in your house if that option is open to you, but safety is a huge concern when covering new territory. One idea to vent your hot air is to cut a hole in the ceiling and run insulated ducting through the ceiling. The ducting should run all the way to an outside vent to prevent heat and moisture buildup in your attic, which can ruin the structure up there, so make sure the crawlspace is big enough for you to get up in the attic and work.
If you’re doing this, make sure to check out the gaps between your ceiling beams ahead of time to make sure you can run the ducting through without cutting through any important framework. Running ducting into the floor and under the house offers another option (if you don’t mind a little tangling with cobwebs). If you happen to have a convenient chimney near your grow spot, that can also be a lucky option. Always get a second opinion regarding safety if you’re making any structural changes to your home.
No matter what, figure out your exhaust system ahead of time when first choosing your room!
How much home-grown weed do you want to produce? How many patients are you serving?
- Stealth Boxes, Small Tents, and Cabinets (up to 2’x4′ or 3’x3′) – yields up to several ounces
- Hobbyist Size Tent – (larger than 3’x3’, but no larger than a 5’x5’) – yields from several ounces up to about a max of 2 lbs
- Large Rooms/Tents – (larger than 5′ x 5′) – yields 1-2 lb and greater
- A Few Example Setups
Remember that you need enough height to support both your lights and plants, so a 3′ tall cupboard isn’t going to cut it if you’re using LED grow lights! If you’re using CFLs or fluorescent lighting you can get by with a short space, but with LEDs or HPS you need to give yourself at least a foot (and usually more) between the light and the top of your plants, so don’t forget to consider that! The more you want to yield, the more height you need (up to a point of course) because bigger plants tend to yield more bud than small ones.
In addition to the space needed by your plants, you also need room to get in and around your plants so you can tend to them. Resist the urge to fill every space in the room because if working on your plants becomes a hassle, you may not do it at all, a negligence that will surely lead to problems with mold or bugs in the future.
What about the other appliances needed for growing premium homegrown weed? Where will you hang your fan and carbon filter? Will you mount your oscillating fans on the walls, or will they just stand in the aisles? Do you have room for a dehumidifier or even a heater should the need for either arises?
When your grow space is completely filled with cannabis plants, it becomes almost impossible to tend the plants near the back and sides
Break out a paper and pen and draw a to-scale diagram of your room, deciding where each item will go beforehand. You will likely need to redraw the diagram over and over before coming up with the perfect layout for your room.
If I have one piece of advice, always give yourself a little more space than you think you need! It’s better to have too much than not enough!
4. Noise and Smell
Perhaps your neighbors cannot see your room, but will they hear it through the walls–the rattle of oscillating fans, your exhaust, and the hum of the ballasts? Perhaps your guests will never pass by the door to your grow, or perhaps the door will be cleverly concealed to the point of invisibility. But will the location adjacent to the living room make it impossible to mask the smell?
Will the grow affect your social life, or can you find a location in your home more fitting?
Of course, there are ways to deal with smells and noises, like carbon filters, hanging equipment from inside the tent, sound boards as well as other techniques, but plan ahead so you know which measures you need to take if any.
5. Moving Supplies In and Out
No matter how well-concealed your room, you will need to move supplies as well as finished medical marijuana in and out each time you harvest. If living in a residential area, you can find a house with an attached garage so you can easily pull your vehicle in to unload. However, many growers with garages find it the optimal place for farming home grown weed (lots of space, minimal damages, and easy to hide from nosy guests).
If you’re growing in a room in your backyard, as discussed before, how will you get stuff in and out in front of the eyes of suspicious neighbors? How will you move harvested plants out? Smuggling stuff in boxes, contractor bags, and plastic totes at night could help provide the answer… Plan, plan, and plan some more!
How will you discreetly move stuff (including plants and supplies) in and out of the grow space?
6. Running Electricity
Running electricity provides yet another challenge. The wiring in a spare bedroom may prove inadequate for running a set of 1000 watt lights as well as the other high-voltage electrical appliances like ACs. If you’re going for a big grow, chances are you’ll need to run a whole new source of power from the fuse box. And the farther you run that power, the more inefficient it becomes. Where will you run the power cables to keep them from being seen? Through the attic? Under the house? Always consult with an electrician before attempting to make any changes to the electrical system in your house!
However, for a smaller hobbyist size grow your house will likely be able to handle the electricity! At that point, it’s more a matter of figuring out how much electricity is going to cost!
Finally, damages to your home present another major concern for the indoor medical marijuana grower. Measures for minimizing the effect of humidity and heat go a long way, but given time, these elements take a toll nonetheless.
Can you afford to sacrifice a little wear and tear on that extra bedroom? Using a room meant for utility purposes, like a shop or garage, could spare the home interior, or should you just take all the necessary precautions and set an additional fund aside for repairs later?
One thing that may help is to use a cannabis grow tent, since these are at least designed to contain spills and other common causes for damage!
But aside from a grow tent or building a room specifically for growing home grown weed, you will surely find that every room has its advantages and disadvantages. You cannot change that. But you can plan well in advance, and by foreseeing future challenges, you can come up with a plan that minimizes or dissolves all of them from the get-go!
To find out more about planning out your indoor grow room, you might want to check out the complete marijuana guide I recommend and e-Book, Growing Elite Marijuana. Learning how to grow weed indoors takes time and energy – rely on those who have gone before you and reap the rewards!
About Sammy Spade
Sammy Spade is a Humboldt County native and writes articles about growing premium pot to help new growers succeed on every single grow.
If you grow weed indoors, this list of 7 guiding principles will teach you how to create the perfect grow room.