Building Your own Cannabis Grow Room

PART 1 / Lightproof

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. Disrupting the 12-hour night period leads to lower yields or even completely failed harvests. That's why you should go stand in your space if this is possible and take a look to make sure that no light is creeping in. If there is, then you can get a special light-proof tape that will blot out the holes and cracks. A grow space that is not lightproof can easily mess up your harvest because the plants will become confused. One of the most easily preventable things that can happen is the creation of male flowers on the female plants thanks to the stress they have been exposed to. In no time at all just a few male flowers can fertilise the whole female planting, with the result that you end up with buds full of seeds.

growing space for cannabis

A good grower always checks his plants so that he can remove any male flowers in good time. It takes a few weeks before a male flower can disperse active pollen. It also happens frequently that the plants find it difficult to come into bloom when beams of light are allowed to get in and they will as a result produce a very meagre crop. Above all watch out that any electrical appliances left in the grow space or destined to be left in there, because these usually have tiny lamps that give off a lot of light that can disturb the night's sleep of your plants. Stick a piece of light-proof tape over any lamps and lights.

PART 2 / Airtight

Once our plants are well and truly in bloom and are producing gorgeous buds, the development of their smell also begins to at a pace. Our plants will begin to spread a fragrant and somewhat powerful odour, which makes it vitally important that our grow space is also made fully airtight. The grow space must have a minimum of cracks or holes in it from which the marihuana odour can escape, and preferably absolutely none. Once your plants begin to smell then you will probably be visiting your crop so regularly you will get quite used to it. In this way you can become convinced that your plants are making little to no smell, when in fact neighbours or fellow inhabitants are suffering from the stench. One other important factor in addition to the safety aspects of having an airtight space is the control of the climate. Creating a good climate is enormously important if you want to get the very best from your plants. So make sure when you are setting up your space that unwanted smells can neither get out nor drafts find their way in. A third important point is that any undesirable creatures and vermin cannot find their way in to your space. A good grow space is in effect a kind of quarantine cell in which nothing gets in or out without your say so.

indoor marijuana growing

PART 3 / Climate

Once we have the previously described points firmly sorted out then we have arrived at our eventual goal of setting up the grow space, creating an ideal climate in which our plants can develop into real giants, growing and blooming at unheard of speeds. Because the climate has to be constant and even throughout your grow space we need a ventilator (or more than one) to make sure there is a good movement of air. The plants will also grow thicker and stronger in the stem and will at the end yield more than plants raised without a ventilator. If you have a good budget at your disposal then you might want to invest in a thermostat, hygrostat or a thermo- hygrostat. You can connect up the thermostat to the exhaust ventilator, which will allow you to set your desired maximum temperature - say, 28 degrees - for your space. If the temperature rises above that, then exhaust ventilator kicks   in to bring it back to 28 degrees. The hygrostat can also be coupled to the exhaust ventilator to make sure that the required air moisture content is maintained. If your space becomes too humid then air is sucked out until the right level is reached. With a dimmer switch you can regulate the speed at which the ventilator operates, so you can run it continuously at a slow speed to keep fresh air pumping intoyour space.

PART 4 / Air moisture

In order to regulate the air moisture content we will need an air humidifier. They are not too expensive and well worth the investment. The nice thing about them is that they usually come with a built-in hygrostat so that you only have to punch in the required air moisture and the humidifier takes care of keeping it there. Especially during the growth period this works wonders.

A plant can double its rate of growth in humid air, and this will help reduce the time spent in the growing phase. Warming a large room or a small growing space will make a world of difference. Letting the air moisture rise during the first weeks is easy in a small space, but try it some time in a whole room. It's just as easy in a large space but then you will need a whole load of expensive equipment and as a beginner you 're better off trying to keep your set up low budget. Now you can just as well throw some decent money at getting your space well insulated; each to his own. We also need to make sure that on one side of the space, down at the bottom, there are holes for air to enter. These holes are to let new CO2-rich air get in. On the other side of the space, right at the top, is where we place a suction pump. This will suck up and remove the warm air. Warm air rises, which is why we place the pump at the uppermost point of the space, or at least the highest possible place. By fitting a carbon filter to the suction pump we can remove at the same time any strong odours.

A carbon filter and vacuum pump go together hand in hand and are absolutely essential in a garden set up such as we are building. A filter will suffice for around five harvests, or about a year. The pump must be of appropriate capacity for the size of the grow space, so first you have to calculate the volume of that space. Casting your minds back to school, we know that multiplying length x width x height will give you the volume of your space. Always take a pump with a slightly larger capacity than the actual volume of your space.

During the hot summer months this can make a big difference in keeping your growing space at a reasonable temperature. Consequently, choose a larger capacity - for example, for a 500 m3 space we might choose a ventilator suitable for a 750 -1000 m3 space.

cannabis grow tent

The great advantage of this is that during the cooler winter months we can let it run gently and using little energy, the during the hot summer months we can let the throttle out and comfortably keep the temperature below 30 degrees. A large ventilator running at half speed makes a lot less noise than a smaller ventilator running flat out.

Also, should you wish to increase the size of your grow space in the future then there is no need to buy a new ventilator. You can never buy a ventilator that's too large, only one that is too small. It makes little sense to keep a ventilator running flat out if it can keep the space replenished with new air at half speed just as well. By placing the air input holes at the bottom of the space and the exhaust at the top we create an air stream that will carry the new, enriched air from below, right up to the top on the other side of the space, flowing over the plants as it goes. This is great forthe plants, which can enjoy the fresh air to the max before it is depleted of CO2, sucked away and removed from the space. In order to keep pests outside we can use a Nylon stocking or special socks placed over the air input holes so nothing can fly or creep in, which will help you avoid an infestation later. Certainly do not forget either that no light must be allowed to get in through these holes to reach the space. PVC tubes with a bend in them work well to let air in but keep light out.

There are thousands of ways of making sure there is a good air supply to your space; they're all great, but there are two main rules to bear in mind: by preference, air in at the bottom, and keep it light-proof. In a situation where you simply cannot make a hole for the pump anywhere then the best solution is to buy a cheap door and make a hole in that for air extraction. This is a frequently used method by professional growers.

PART 5 / Square metre

That's enough wittering on; the real work is about to start: the actual building of the grow space. You do not need much for it: just a single square meter, and everyone has that somewhere, whether in the attic, cellar or a spare room. What we need is: a staple gun for use on wood, a saw, black-white plastic, a drill, screws, scissors, a few wooden planks - and a square metre. What we are going to build is a screen around the growing space. Let's suppose you do use a single meter of a large room, then it is handy to PARTition off the grow space from the rest of the room so this can be used for something else. If you don't do this then the whole room will stink later when the plants are blooming.

The big advantage of building a screen is that the light from your lamp will be utilised to the full. Light is weight - that is to say, the amount of light a plant gets will to a large extent determine the eventual yield. By building a screen around the square meter that is then covered in white reflective plastic, you keep the light inside the growing space and on your plants. If you don't do this then the light will scatter itself all over the room and so you will lose a good proportion of it. Making sure that the sides around your plants are of reflective white is the cheapest way of raising your yield. It don't get any cheaper or easier. Mylar is the best stuff currently on the market for reflecting light back on your plants. It is a little more expensive than black-white plastic but reflects some 99% of the light that your lamp gives off back at your plants. Mylar needs to be hung as straight as possible to be best made use of.

indoor marijuana growing

It's very important for the set up of your growing space to make sure it has reflective walls, whether these are white walls or hung plastic makes no difference.

The construction of a screen is a half-hour's work once you've got the necessary materials mentioned to hand. I cut eight pieces of wood about 1.2 m long, and six pieces of about 1.70 m. I arrive at this length (1.70 m) as a result of my cellar ceiling being so high. The length you choose is best when a little shorter than the height of the room or space in which the growing space is to be situated. If your room is 2 metres high, then cut eight lengths of about 1.97cm. In other words, subtract a few centimetres from the actual height of the room. Step 1 is pretty simple: we make a wooden frame by attaching two pieces of 1.2 m wide to two pieces (in my case) of 1.70 m in height. This is done real fast with a machine drill on which we place a piece the two bits that need fixing together, drilling a hole and screwing them together. Once we have our wooden frame securely put together we can stretch the black-white plastic tightly over it. This is done most smoothly using a stapler to staple the plastic in place. Excess plastic can be trimmed away once it's attached. So now we have our first reflecting screen. Onto this we need to attach one more screen in the same way as we just did the previous two, only using one piece of the 1.70 m wooden struts less. We just use the 1.70 m plank on the screen we've just made and attach to that two pieces of 1.20 m and one of 1.70 m. Stretch and staple plastic over it and again, trim off the excess.

Now we have two pieces of screen attached to each other. In this way we don't make separate loose hanging screens. On the other side we do the same and make a screen there too, attaching it to the already existing wooden strut of the first screen. The result is that we now have three screens firmly attached to each other and with reflecting surfaces. This construction you now place in the chosen square meter that's your grow space. As we've already noticed, the screens are a little bigger than the growing space. This is so that we still have room for the ventilator and suchlike to fit in. To finish off, we once more make a single independent screen with two pieces of the 1.20 m wood and two of the 1.70 m planks.

The individual, loose hanging screen is the entrance door to the growing space. We put this against the open side of the three screen box, and our growspace is fully sealed off. Now all you have to do is move the screen door to inspect and care for your plants. Now the light from the lamp stays in this way in the growing space and you will notice the difference this makes later when you come to harvest your plants. The smell of the plants is also kept inside and can be easily removed by filtered pump, so the rest of the space in the room you can put to some other use. Really creative growers of course can make a real jewel of a grow space for themselves.

cannabis indoor growing tent

PART 6 / Collection Rack

A grow space should be easy to keep tidy, and that's why I choose to build in a sort of 'collection rack' into which the plant pots will be placed. To do this we build a frame 1.10 m wide, with a length of your choice, and a height of 15 cm. This is lined with the same black-white plastic (ensuring there are no holes in it now or later on).

The advantage of such a rack is that it just makes for cleaner growing and this gives diseases less of a chance of gaining a foothold. All rubbish such as soil, dead leaves and splashed water end up straight in this rack. Once the harvest is over it is very simple to just sweep all this together and clear it away and in no time everything is spick and span for the next planting. If you don't use a collection rack then, as many growers do not, then in no time at all your space will be transformed into a space or room with a bit of dirt everywhere you look. Also, if you have to flush your crop such a collection rack will prove its worth. 'Flushing' is the removal of excess nutrient or fertilizer from out of the medium (plant pot). By giving the plants way too much pure water the nutrient residues are washed out, as are the salts that accumulate from over-fertilizing(salts are found in fertilizer).

Some growers choose simply to flush as a matter of course every two weeks in order to keep their medium as healthy as possible. With a collection rack you can flush the plants without any problem and without leaving a wet mess behind in your space. Another advantage is that when growing in soil you can let the whole rack fill with feed water and leave the plants to take what nutrients they need from it. This is the same effect as a plant pot standing in a tray. You have in effect made an enormous tray, in fact. The good thing about this is that the plants will be more difficult to over-fertilize because the plants themselves decide how much they are going to take up. If you need to be away for 3-4 days then you can just leave the collection rack topped up and the plants have enough food for those few days. The rack then serves as an automatic watering system.

Later you can easily switch up to an ebb and flood hydro system. So to recap: our aim is to make a light-proof, airtight grow space in which the fresh, CO2-rich air comes in at the bottom of one side of the space, circulates up and out the other side. A sufficiently large suction pump ensures the air circulates and ventilators mix the fresh, incoming air with the air warmed by the lamp so that the temperature is the same throughout the space. Just add reflecting walls to maximise the effect of the light and a collection rack for keeping everything tidy, and Bob's your uncle. The grow space is now ready for planting!

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