1. Intro To Basics
Back to the basics.
Let me start with some of the basic facts on growing plants.
Like any other living thing on our planet, a plant needs water, air, light,
food, and warmth. Take one of those things away and your plants won't grow.
These are the main factors in growing anything at all. You could have a
perfectly built greenhouse but if your plants don't get any water they die.
More than 75% of a plant's weight is water.
Besides being used as transportation-medium, about 99% of the water absorbed by
the roots will be used to keep a plant cool.
This works the same as with us human beings: by evaporating water, heat is
absorbed which results in a cooler body.
The remaining 1% will be used in the plant's photosynthesis
process. Photosynthesis is a complicated process
where the plant builds carbohydrates from water, CO², and light-energy. These
carbohydrates are later combined with other chemical compounds absorbed from air
and soil and transformed into new plant substance.
Also, 'additionally' Oxygen is formed as a waste product.
This process is the start of the food- and air-chain; plants play a very
important role in life as we know it.
It seems that everybody understands the importance of light and water in the
process of Photosynthesis. But the third factor, being CO², is
I won't go into much detail here because you don't have to know what makes an
engine work to drive a car, but have a short look at CO².
This formula tells us Carbon Dioxide is a molecule made of one Carbon and two
Oxygen atoms. The Carbon atom is of importance here (Oxygen was just waste,
remember? If life would be that simple ;-):
the problem is that there is only one Carbon-atom in each molecule. Also you
have to keep in mind that there is only about 0.3% CO² in normal air. So maybe
now you understand why air is of such importance.
Let's make a quick jump to light.
As I already told you the energy of light is used to form carbohydrates like
sugar, starch and cellulose.
Of course this can only take place if there is a source of light available. The
light we see from the sun is a mix of all colors. Plants use mainly blue and red
light, depending on the growth stage.
So here we get another problem, since we are growing indoors where the sun
refuses to shine we have to use another light source.
One problem is that normal bulbs don't give enough light for a plant, but the
main problem is they have the wrong color. At this moment the only lamps giving
enough light in more or less the right color are Metal-Halide bulbs.
For the vegetative (= growing) stage of a plant's lifecycle you need more of the
blue light. You could use high-pressure mercury lamps but since growing doesn't
take that much light and you are probably only growing your own seedlings or
clones you could just as well use fluorescent tube lights (color cool white).
Flowering marihuana asks more red light which seems to be more of a problem.
At this moment, and as far as I know, the best results come from high-pressure
The best you can get are Philips® Sun-T plus™ bulbs, and I don't say that
because I'm from Holland (they are made in Belgium anyway).
Another thing that has to do with light is Photoperiod, the
relation between the length of day and night in a twenty-four hour period.
Marihuana is a short-day plant, which means it will start flowering at twelve
hours light and twelve hours of darkness.
Long-day plants will do their thing after they have reached a certain age, but
let's stick to short-day plants.
Although marihuana is a one-year plant you can force it in a certain growth
stage by 'fooling' it with the length of light. Change the period to 12/12 and
it will flower, keep it at 18/6 hours light/dark period and it will grow 4ever.
Okay, we have had light, water and air. Let's go eat.
After eating, our meal is digested in our stomach. Another weird chemical
process involving things you may not want to know about. Because our cells can't
do anything with let's say a piece of banana, it's ripped apart in molecules and
elements which our body cells know how to handle. Among other things acid is
being used to split complex molecules into easier to handle smaller molecules
The same goes for plants, they can't nourish on the complex molecules you'll
find in the medium at which they root, be it soil or rockwool. Because they are
not equipped with a stomach they're in a bit of a disadvantage, their food has
to be pre-digested so to speak. And although a plant is not as helpless as you
might think, it helps to keep the growing-medium a bit on the acidic side of the
famous pH scale so your baby's roots won't have such a hard
time picking up nutrients.
And finally; since eating and growing means work and all work costs energy
this is where warmth gets in. If a certain temperature is not reached, there
will not be enough energy for the process to start up, or things will happen at
a lower rate. This is especially true for roots; the temperature at the roots
should be at a minimum of 20 degrees Centigrade to a maximum of about 28
degrees. Air temperature is mostly not a problem, keeping your feet warm is of
Now all of the above; water, air, light, food, and warmth are essential
growing-factors. They all have to be in order or you will find that things won't
go as planned. Building a good environment is our first goal; I'll cover that on
the next pages.
Simple isn't it?
Like I said, just like riding a bike.
To convert Centigrade to Fahrenheit: C x 1.8 + 32 = F
2. Intro A Place to Grow
Weed is grown in all kind of places, perfectly built greenhouses, closets,
basements or spare bedrooms. Every place has its advantages and drawbacks but
some things just go for any room.
- You don't want any light to enter or leave the room.
The brightness, but especially the color of the lamps we use will certainly
draw attention from your neighborhood. Most of us can live without this
From the plants point of view it's of even more importance no light gets in.
The hormone triggering the process of flowering is formed at night and
destroyed by light. Only if the plants are kept in total darkness for twelve
hours per day this hormone will gain enough power for the plant to flower.
And I do mean total darkness here! Even the slightest trace of light will
delay or even stop this mechanism from taking place.
- You want air to get in and out as much as possible.
- You need electricity, and to stay on the safe side it has to be grounded
- A tap makes life a lot easier; marihuana-plants use a lot of water. Since
growing hydroponics means you have to flush the growing media on a regular
basis, a way to get rid of the 'waste-water' also comes in very handy.
What would be a perfect room for you to grow weed depends a lot on the
climate you are living in. In a dessert area you would meet other problems than
in the coastal region I live in. Where I have the problem keeping humidity low,
maybe for you the problem is getting it high enough. But since we still have to
find and build a place for our indoor garden let's first have a look at the
drawbacks and advantages of certain spaces.
The main problem with attics is the temperature, in summer it will get to hot
in winters your plants freeze. 'Reversing' day and night will sometimes help a
Another problem with attics could be that it's just not high enough to hang up
Bedrooms offer good opportunities; temperature can be a bit of a problem,
especially if the room is situated on the south side.
On the other hand, most of the times it is simple to adjust the room to your
plants needs because walls and ceiling are flat and straight-cornered. There is
still some constructing to do, you know?
A problem could be the windows that have to be sealed of, so no light can get in
or out. Simply nailing them shut with plywood could attract some attention, so
at least please your neighborhood by first hanging up a nice curtain.
Windows could be used to get fresh air into the room, but I wouldn't use them to
get stale air out. Because of air turbulence around the building you would never
know where the bouquet of the weed goes. Also strong winds might blow the air
in, consequently impeding your ventilation from working properly.
Most of the times basements will have a constant temperature and humidity,
which makes controlling things a lot easier.
Getting enough air in and out, as well as getting rid of water, could be the
problem here. If you would have a chimney or the likes to get rid of the
exhaust-air, the place would be near perfect.
Don't just simply place your plants on the floor, it will be too cold for the
roots. Building a low (about 1-foot) table will not only prevent your roots from
getting to cold, it also simplifies catching run off water. If there's not
enough room for a table, at least place your plants on a layer of Styrofoam.
Reversing day and night.
With this I mean your lamps burn at night and are off during daytime.
The benefit being that temperature is 'smoothed out' a little.
At night, when it gets cold in winter and cool in summer, your lamps will warm
up the place. During daytime, in summer you won't heat up the place even more
with the warmth of the lights, while in winter you probably would heat up your
house more during day- than during nighttime.
Of course there are also some drawbacks:
You have to work at night because you're not allowed to make any light during
the dark period of your plants.
Also every indoor garden makes some noise: lamps hum, ventilators vibrate, etc.
and as we all know sounds carry further at night than during the daytime.
And last but not least, it could be that by reversing day and night your plants
might experience 'night' temperatures just as high or even higher than during
its 'day' time. It looks like this has a negative effect on the forming of big
buds. It seems Haze likes cooler nights, especially at the end of it's blooming
In an effort to make things not more complicated as they already are, when
speaking of day or night from now on I mean:
"from the plants point of view."
As I always feel that most people growing indoor weed underestimate the
importance of air, this is what I will cover on the next pages.
How do you get air in and out, without light shining through? What to do about
As a matter of fact air is quit simple because there's only one thing to go
wrong: Not Enough Of It.
Commercial greenhouses have the ability to change the complete volume of air in
about two minute's time. Maybe this is a bit overdone for our purposes, but it
shows us the significance of air for plants.
As I already told you, the carbon dioxide in air is needed for the plant's
photosynthesis process. In a closed environment, plants could use up all of the
CO² in less than half an hour, especially when it's hot.
In exchange oxygen, water vapor and odors are released to the air, which we want
out of the room ASAP.
The process of building sugars under the influence of light and CO² is
At night, from these sugars new cells are formed, a process we call
dissimilation. For the latter process oxygen is used. Also roots need oxygen as
a source of energy, to much CO² at root-level could even be poisonous.But
generally speaking plants produce a lot more oxygen then they use themselves.
In modern greenhouses CO² is sometimes added as extra nourishment. Especially
with higher temperature's bigger harvests are possible.
A word of advice: although CO² can result in better yields I
wouldn't use it inside my house. The gas itself is not poisonous, but it is
dangerous because it is heavier than air, and it will not just mix: it tends to
replace the air.
It also replaces the oxygen in our blood, so you would simply suffocate.
In other words, if anything should go wrong, you, your children, visitors, or
your neighbors might never wake up.
Getting air out
Getting enough air in and out of the growing-room is one of the biggest
Although Haze doesn't smell as bad as Skunk (well, that's my opinion ;-), there
still is a considerable amount of smell to get rid off. Besides that the plant
needs a lot of fresh air (I know; I am repeating myself).
If you only have one lamp in an enormous room there is not much of a problem.
Difficulties start when your room is smaller or when you have more lamps. In
this case you really need the help of strong ventilators plus some sort of
passage to get air in and out.
Chimneys are near perfect, well if not in use that is.
Sometimes you don't even have to worry about smell since chimneys are designed
to get their exhaust into the higher winds.
Apart from that there's always a bit of natural draft so even when ventilators
are out you'd have some ventilation. This could be an advantage at nights.
During daytime (When the lights are burning, remember?), this natural
ventilation will hardly be sufficient so you'll have to help nature's forces a
bit by means of a mechanical fan.
If you don't have a chimney or another kind of funnel, you'll have to
fabricate something yourself.
As a last result you could simply run a hole through the wall. Aside from
attracting attention, strong winds might stop your ventilation from working
properly. There's also the problem of not knowing where the smell will go.
A way to avoid problems with smell is to make use of an activated carbon filter.
This would take care of 99% of the smell. Filters however cause extra
resistance, as do flexible hoses and curved funnels. This is something you have
to take into account when buying a fan.
Getting air in.
IMHO one fan should be enough for your ventilation-system to work.
Use it to get the air out, if possible from the top of the room. By making a
hole on the opposite site of the room air will be sucked in due to the
underpressure caused by the fan. Of course you could make more then one hole to
get air in. As a rule of thumb make the surface of the hole(s) were the air
enters three times bigger than the surface of the hole you use to get air out.
In contrary to the problem where to leave stale air, it doesn't matter too much
from where you obtain fresh air. Depending on the climate and the time of year
you could get it in from your house, nicely pre-heated in winter. In a hot
summer you need lots of air, so you get it in from as much places as you can
An advantage of using only one fan to get air out is that air gets sucked in
through all cracks and holes that might be in your room's walls. Because of
this, it is humanly impossible that smells do escape by any other way than you
intended (i.e. through your filter).
We still have a major problem, how to get the air in and out, without light
seeping through the holes? The answer is in Greek mythology, a labyrinth.
A labyrinth is a construction that allows air to enter (or leave) freely,
without allowing light to pass through. To save a thousand words I will add a picture, albeit a very schematic one. On
this picture you have a view from the side, and of course this side has to be
closed too. You can make one from a cardboard box, black and white plastic, or
If you want to do things as they should be done, make one out of triplex or any
other plywood. To keep light from reflecting, use black non-shining paint like
the one they use for chalkboards, and paint the whole thing black. Make it as
big as possible to reduce air flow resistance.
It's not easy to say what fan is the best for our goal.
One thing's for sure though, apart from the lamps, it's the most important piece
of equipment you have to buy so don't try to save money here.
Off course you are restricted to the measure of the funnel used as an exhaust.
You simply cannot push 2,000 cubic meters of air through a 125 mm tube. Also
long ducts with curves, filters, etc., add up to more resistance, which you have
to take into account.
In accordance with all of the above you can calculate the maximum capacity of
the fan you need. Or you could have someone with experience in air-conditioning
calculate it for you. Buy the maximum-capacity fan you could use, not a lighter
Remember that you can always use a dimmer to reduce the airflow of a heavy fan,
but you cannot make a fan run any faster if its capacity is insufficient.
Probably the best buy for your money is a squirrel cage ventilator. They are
relatively cheap to buy and also have the best relation between electrical
power-consumption and airflow.
Watch out for bargains when buying a fan.
Cheap fans could produce a lot of vibration because of bad construction and
these vibrations carry a long way through walls et cetera.
It's possible that you don't hear a thing, but a few blocks away people can tell
exactly when things start up with you, because of the resonance of the
A remedy for this problem is to mount the fan to the wall with rubber blocks (go
to a Harley-Davidson dealer and ask for the blocks to mount an oil-tank).
Another way is to hang it from the ceiling using rubber straps.
By using a small piece of flexible hose to attach your fan to the exhaust-funnel
you prevent vibes passing through here.
Another source of noise could be the hissing sound of the air being blown out.
Try to make the inside of funnels as smooth as possible to keep turbulence to a
Moving the air around
Besides a fan to get air in and out, you need a few normal fans to keep the
air in motion.
The oscillating tabletop-fans you can buy at any hardware-store are ideal for
this purpose. For the reason of why we have to move air around we need some more
Water and nutrition is picked up by the roots and transported throughout the
plant. The mechanism behind this transport is rather complex and still not fully
It's a combination of roots giving pressure, osmosis from the cells and the
transpiration through the (stomata of the) leaves.
Plants do not have an active breathing-system as we humans or animals have. If
the air around the leaves stands still, humidity will rise and affect
evaporation, thus decreasing the total sap-flow.
Also the plant will use up CO² in unmoving air in no time, so you have to make
sure it is refreshed continuously.
Furthermore, by moving the air around you won't get local differences in
temperature and humidity, and insects and molds are having a harder time.Last
but not least, plants get stronger from the motion induced by the flow of air.
Because Haze plants tend to get big, it's always a good idea to ventilate below
the canopy of leaves as well.
A very nice way to equalize temperature is vertical ventilation.
During the summer, one could pump the relatively cool air from the floor to the
ceiling by means of a fan and hose. During the winter, turn the fan around so
you pump the warmer air down.
If you use vertical ventilation you need to vacuum-clean your room a bit more,
because of dust being blown around. But having a clean room also helps avoiding
pests, like bugs and molds so you have to clean regularly anyhow.
Remember that gardens with the most fans most of the times have the best
results, especially if they are in use.
In case you're using non-oscillating fans to move air around internally, don't
directly point them to your plants. This will cause windburn on the leaves.
Fans need to be started "full speed", after this you could turn them
down a bit. Oscillating fans also have to be moved around, which makes things
harder for the (small) engine.
Never, ever use a time clock to switch a ventilator unless it
is set full speed, it could be that it "hangs" and won't start up at
all, which could cause a fire.
Most of us will start growing Haze with clones or cuttings, as it is hard if
not impossible to get seeds.
The starting plant, be it a clone or a seedling, doesn't need very much light to
start with. You could very well use fluorescent tubes (color 33, or cool white).
If you would mount them 15 cm. (6 Inch) apart you would have sufficient light to
start up clones or seedlings. Keeping them 7 cm (3 in) above the fresh cuttings
would be a nice start.
Because the little amount of heat produced by these lamps, there's no real
problem should the clone touch the lamp later on, once it starts growing.
For flowering marihuana, fluorescent lights are not bright enough, and are of
the wrong color.
Actually, with light it's the same story as with air. That is, you want as much
as possible. And this is where High-Intensity Discharge (HID) lamps come in. At
the moment there are two kinds of HID lamps suitable to grow plants indoors.
- Metal Halide (MH): give a whitish color of light. It's perfect for the
vegetative (i.e. growing) stage of plants.
- High Pressure Sodium-lamps (HPS): give a more yellowish color. Because
more red light is produced by this lamp, these are the ones we want to have
for flowering our plants.
I already explained that the white light we see from the sun, actually is a
mixture of all colors.
At this moment, it's technically very difficult, if not impossible, to copy
sunlight. It's a lot easier and cheaper to fabricate bulbs that produce only
light in one color or portion of the spectrum, the so-called monochromatic
light. Sometimes these monochromatic (Low Pressure Sodium) bulbs are used to
enlighten highways, streets, and parking lots. And because of the fact that they
only produce this one color (yellowish-orange) they are absolutely inadequate
for our goal, namely to force weed into bloom.
You absolutely need the agricultural HPS bulbs and the appropriate lighting
device to flower weed because these bulbs will also produce light in the blue
area of the spectrum.
All of the bulbs mentioned above, including fluorescent tubes, require special
"ballast's" to start up. These ballasts are not interchangeable, so
please don't experiment with using the bulbs in the 'wrong' device. Even if your
HPS bulb would 'work' in a MH device, you're literally playing with fire.
Besides this fire risk, your bulb would probably not produce as much light as it
could when mated with the appropriate ballast.
Metal Halide and HPS bulbs need time to heat up before they achieve maximum
output. Besides that, once turned off, they need to cool down before they can be
started up again.
As we all know ;-) following the inverse-square law, the amount of light that
falls on a given area weakens to one-fourth if you double the distance.
Because Haze tends to grow big, this is something to take into account. The
amount of light produced by even the strongest HPS lamps hardly meets the
plant's needs, this means the lower parts of your plants don't get as much light
as they should. The only advice I can give here is to make sure that every wall
inside your growing-room is painted white, preferably with old-fashioned
chalk-paint. Because of its rough structure, chalk gives the best reflection.
It's also more diffuse than the reflection of other materials, such as plastic,
and plants seem to benefit from it.
Still, it's always a good idea to keep your lamps at the closest distance
If you use 'deep-beam reflectors', which are perfect for our goals, this
distance is about 40 cm (15 in.). With the so-called 'wide reflectors' you could
even lower the lamp some more.
As a rule of thumb, I can say that you have to watch the leaves closest to the
bulb. If they start curling, you need to increase the distance between bulb and
Although a wide range of outputs are available, I prefer 400 Watt HPS lamps
for flowering. I would only use 600-Watt lamps to grow a relatively big yield on
a small area, like a closet.
The heat generated by these lamps can be significant. In spite of this, I think
two 400-Watt lamps are a better choice than one 600-Watt lamp.
So, if you are 'just starting up' but plan on maybe grow bigger, buy 400-Watt
lamps; they are a better investment for your future.
Hang them about one meter (3 feet), apart and use pulley blocks so you can
change the height according to the growth of your plants. More lamps usually
give better results because the light-beams overlap each other. Especially
plants in the middle feel at their best, because the light is coming from all
Because of the high currents required by the lamps, it's best to pay special
attention on the way you connect them.
The safest thing to do is to wire them separately on their own circuit.
What we also need is a good quality timer to switch the lamps on and off.
Again here lies a problem. When starting up the lamps, the ballast will draw
about 30% more electricity than during its normal burning hours. This will cause
a spark that will destroy the switch in the timer. The switch will 'hang' so
your lamps won't go off, causing disaster for your plants because all of a
sudden they get 24 hours of light per day.
Besides that it could start a fire, so never directly connect your lamps to a
What you need is a relay; this device is specially constructed
to safely conduct the high currents involved. Because the timer is only used to
steer the relay, which only takes a bit of electricity, this is the one and only
safe way to turn on your light!
Again I want to emphasize the importance of your room being completely sealed
of from other sources of light.
A lot of harvests already are gone to smithereens because of someone being too
curious, and snooping in during the dark period.
Remember, even the smallest amount of light during the night will cause your
plants to delay blooming. Too much light during the night could even prevent
blooming at all, keeping the plant in its vegetative lifecycle.
Make very sure no light leaks in, especially from outside.
The best way to achieve this task is to wait for a sunny day, (first ;-) roll a
joint and than sit in the room for about ten minutes with the lights out. If
after this time you still don't see any trace of light, you can be reasonably
sure it is dark enough for your plants.
Pay special attention to the labyrinths, windows, doors, etc.
Even after this thorough inside inspection, it would be a good idea to check the
outside of the room as well. This inspection round is best carried out at night,
with all the lamps inside burning.
Again pay special attention to windows and other openings.
I sometimes hear the advice to mix HPS light with MH light, the idea being
that the plant would benefit from the bluer light, produced by these lamps.
Although I see no disadvantages, I have never noticed this to lead to a better
product. HPS bulbs produce a lot more light per Watt, and IMHO you're better
off spending your money on these lamps.
The only occasion where I make use of Metal Halide lamps is for vegetative
purposes (i.e. mother-plants and cuttings).
Officially (in Holland that is), the power companies don't allow you to
connect the lamps we use to the net by means of a plug.
On the other hand it does have its advantages, should you decide to turn one
or two lamps off.
Take special care though; never pull the plug while your lamps are at use, in
other words: first turn of electricity by means of the relay, than pull the
plug out. Of course the same rule applies for putting plugs in.
Your Indoor Garden
We've discussed the importance of air and light and how to get air into your
room without light seeping through the holes.
Maybe it's about time to make a decision on how we are going to grow our weed.
In my introduction I already stated my feelings about so called 'bio-logical'
indoor weed. Also I mentioned how I think of automating your garden. I strongly
advise against automating feeding until you know exactly what you're doing, i.e.
water your plants by hand up to the time you know their needs.
After having said this (typed actually ;-), let's go on with the show.
You've picked out your room and of course you gave it a thorough clean up. So
now let's start building.
Depending on which room you did choose, you first have to block the windows.
Remember my advice about first hanging up a nice curtain? Play it safe and tape
or tackle it to the window, so it won't fall down after you have nailed
everything shut .
If your walls are paper-thin, it's a good idea to first add some insulation.
This will prevent problems with temperatures and noise, later on. Foam
materials, especially Styrofoam could cause problems here when water creeps
behind it, a better choice would be rock wool. You can finish of this insulation
with gypsum board (or wallboard), which in my (humble?) opinion is a better
option than plastic-foil.
Plastic will seal a wall airtight, especially causing problems with air
moisture. Wallboard on the other hand will take up the excess of water if
humidity is high, and give it back to the air if humidity drops, thus flattening
If you feel like painting your new walls white - always a good idea - use chalk
or another paint that won't seal off the surface.
Try to make your new walls as straight as possible and pay special attention
to the framework. Later you will hang all kind of things on the wall, or use
them as a fix-point for your lamps, so you better be prepared.
Also you better don't forget to keep enough holes in your walls to let air enter
freely, it would be a shame if you had to build labyrinths later on.
Place your fan as close as possible to the exhaust funnel to prevent extra
If you are going to use a filter device against smells, most of the times you
have to build your (squirrel-cache) fan in a box. With a tube-fan this building
in isn't necessary, but you would need a huge tube-fan to equal a
squirrel-cache. This building in is necessary to provide the under-pressure to
suck the air through the filter. For resistance sake, the inner dimensions of
this box should be twice as big as the outer dimensions of your fan.
Line the inside of the box with Styrofoam or the likes to reduce noise. This
construction is quite heavy in weight, so you need to mount it properly.
Remember that filters and fan should be adjusted to each other. If the fan is
oversized compared to the filter, the whole system just won't work. Activated
carbon filters last for about a year, after which the carbon should be replaced.
NOTE: IMHO if you use a chimney or the likes you don't need a filter because
the smells will go into the higher currents.
Use your own judgement here. If you don't need a filter, you also don't need a
box. This could safe you some money but should someone smell your
"hobby", it would probably cost you a lot more than a filter.
I like to grow weed on low - about one foot high - tables.
It keeps the roots out of the cold draft and I feel it's better for my back (I
am getting a bit older you know?). Also, with a little help from gravity, it
helps in collecting run-off water.
The best thing to do is to build tables with a waterproof layer, tilted just
enough so the excess water will run off . Plastic roofing plates with curves of
about ½ in. work very nice in this context.
Because water will creep back underneath, heat up the ends and bent the lower
end down and the upper end up. Also you should overlap them enough to make sure
no water will creep through.
Do not tilt your tables too much, especially if you use rock wool as a
growing medium. Too much slope will cause dry spots at the higher end of the
rock wool slabs.
Hang 'em high
After all this preparation of the room we're going to hang 'em.
The lamps that is.
As with fans, I like to spend my money on quality here.
Remote ballast lamps are quit popular these days, and they will do their thing.
If heat is much of a problem for your garden, you could consider these lamps.
A much better alternative is to improve your airflow for better cooling and to
use professional lamps instead. Even if they would cost a bit (well, a lot) more
than - do it yourself - lamps, the extra amount of light, plus the longer life
of the lamp, would pay itself back in no time at all. The ultimate reflector for
blooming is a deep beam.
Besides the price and where to get them, the problem with professional lamps is
their weight. I hope you took my advice on building a good frame to support your
Lamps should be hung square-angled to the table with the reflector facing you
(If you only have one lamp hang it anyway it pleases you).
Always hang them on two ropes or chains to prevent them from turning circles and
never hang them from, or stretch the power-cable.
I find rope and tackles easy to use, it makes adjusting height a flinch but
since you only have to rise the lamps the first two or three weeks you could
also use chain.
Whatever you use, make sure everything is tightly connected. If one of your
lamps would fall down because a bolt or chain breaks you are in a lot of
Such and So.'s
Well, of course we're not through yet, sometimes I wonder: 'will I ever', but
that's another story. Four white walls, a fan, a filter, a table and some lamps;
well it's a start, but we need more.
To place the oscillating table-fans you can now mount some platforms to the
walls (I told you that you would hang all kind of thing to the wall).
Two is an absolute minimum, you need a strong one to move air above the canopy
of leaves so place it high. Another is placed just above the table, it doesn't
have to be as strong as the other as long as it prevents the air underneath from
Something worthwhile having is a thermometer which shows
minimum and maximum temperatures.
A very simple (U-shaped) one like you can buy at garden centers will already do
the job. It's only needed to give you an indication of what's a happening while
you were out.
Also a hygrometer could come in handy. Don't spent good money
on cheap stuff here, if you think you need to measure humidity, buy a hair
Because the nutrient solutions are easier to handle in larger quantities,
it's comfortable to have some sort of vessel.
Anything that holds fluids will do, as long as it is made out of (high-grade)
plastic and preferably with a lid.
Besides that you need a small pump to move the solution around in the container,
the ones in use for turtles (about 400 Liter / 100 Gallon p/h) are perfect for
To keep the nutrient at a nice temperature, buy a heater as used for tropical
fish. It's even better to buy two; a heavy one will heat up the (cold) freshly
made nutrient till about 18° C.. A lighter one, set to 22° C., will
keep nutrient at a constant temperature.
Large amounts of freshly prepared nutrient could take up to a couple of days to
heat up without a heating device .
CAUTION. Never ever use metals in, or with your
Of course you could add warm water should the nutrient-solution
be too cold.
If you do, only use freshly heated water like from a geyser. Do not use hot
water from a boiler in great amounts. Because water in boilers stands still for
longer periods of time, it is possible that small copper particles dissolve in
this (hot) water. Copper in greater amounts will poison your plants, so play it
BTW, the same goes for human beings. Don't use boiler-water to brew your tea or
In nature, most plants root in soil.
Rainwater dissolves elements contained in the medium, so the roots can provide
the nutrients to the plants.
Already as early as in the 17th century scientists started laboratory
experiments to find out about the factors that control plant growth.
The aristocracy who liked to grow exotic plant and trees from the 'New World'
mostly did this in their 'orangeries', the hothouses of that time.
Because these plants were grown in pots containing soil, they soon started to
develop deficiency diseases and people slowly started to find out about the
necessary nutrients for plants.
During the ages that followed, the scientists found out that plants could be
grown in different inert substrates or even water alone, provided the proper
nutrients were available.
Around the 1930's studies on hydroponics were done in the USA.
Studies that during WW II proved fruitful when the army grew vegetables
hydroponically with gravel as a substrate. This was done on remote islands in
the Pacific where fertile soil was absent and transport was expensive and risky.
Any instance where plants are grown in a soilless medium is called
Although plants may flourish just by hanging with their roots in a
water-nutrient solution, all kinds of inert substrates are used to support the
roots. Among others sand, gravel, perlite, and peat were, and still are, in use.
Experiments were done with peanut shells and lately promising results are being
reported by using coconut fibers as a growing medium.
Maybe the weed grown on these materials would drive you nuts. Since I'd rather
be stoned let's rock wool. (Well actually I'd rather be high, but there's no way
one can grow weed on air alone ;-)
This material was first found in Hawaii where it is natural volcanic product.
The locals thought it to be the hair of Pele, who was the goddess of the
volcanoes (Haw lauoho-o Pele). She would pull out her hair in anger and throw it
around, making a lot of noise and fire in the process.
Already in the midst of the 19th century rock wool was produced in the USA as an
insulation material, mainly for steam engines. Nowadays it is still used a lot
for the insulation of buildings, your own walls might be chock-full with the
In the late sixties, rock wool was first used commercially as a growing
substrate in Denmark (of which Holland is not the capital, mind you!).
Today it's the most used material to grow plants and veggies in the Dutch
Once fabricated, it's a clean, inert material that contains no nutrients at all.
This makes it an easy product to control. It has a more or less 'perfect ' ratio
between air and water.
Preparing rock wool
Actually, the new rockwool slabs are a bit on the basic (notice the
lowercase!) or alkaline side of the pH scale.
It's always a good idea to prepare the slabs one day ahead of the arrival of
Mix a mild solution of the nutrient that you are going to use. Half the normal
strength should do the trick.
Now only for once, we are going to lower pH to a mortal value.
Use nitric acid (HNO3)
to lower the half-strength nutrient down to a pH just under pH 5.0.
Watch it here!
Dissolve only small amounts of acid at the time, stir the solution, measure it
and if pH still shows high add another small amount of acid.
Special care should be taken once pH drops below 5.3 because the buffer of the
bicarbonates in the water is broken around this figure.
The amount of acid needed to lower acidity from pH 5.3 down to pH 5.0 is
very small compared to the amount needed to lower pH from 7.3 to 7.0.
If you manage to make the solution as sour as pH 4.5 you're out of luck.
You have to throw it away which is very bad for sewer systems, gardens, and
Mother Nature as a whole, so please try to stay on the safe side and be a little
If pH is (more or less) in the right range wait for a couple of hours to give
the starting nutrient time to really dissolve.
Check pH again, but do not make adjustments if figures are only a few tenths of
When you are happy with the figures pour this solution in the new slabs,
completely saturating them. Let the whole thing brew for at least a night.
This acidic solution will lower the pH in the rock wool to a 'healthy' pH 6.0.
It's best to make enough of this 'preparing solution' so you can fill all of the
slabs in one run since it is almost impossible to make a second with the same
But remember that you just have to throw away all that's left over.
CAUTION! Never water your plants with a nutrient
as acidic as this. For normal watering pH should be around 6.0.
I will talk about pH (a little ;-) more in-depth later on.
For the moment just keep in mind that on the pH scale 7.0 is neutral, higher
figures mean more alkalinity, and lower figures mean a more sour solution.
Also bear in mind that, because we're talking logarithmic here, a solution with
pH 6.0 is TEN times more sour than a pH 7.0, and pH 5.0 would
mean ONE HUNDRED times more H+ ions than the neutral pH 7.0 solution.
There are nice formulas to compute how much acid of a given strength should be
added to another liquid to get a certain pH.
Since those formulas make use of atomic weights and such, but mainly because I
never found it necessary to learn them myself, I will not bore you with that.
Although they appear the same, the two varieties of rock wool are a completely
different product. First of all, the insulation variant is water repellent while
the horticultural grade absorbs an enormous amount of water. Furthermore, steel
and copper slags and cinders from the steel mills are sometimes used together
with the basalt and limestone that normally make up rock wool. These metals may
react with the acidic nutrient solution making life very hard for your plants,
to say the least. Use only horticultural rock wool of a good quality; never use
the insulation grad.
Most of the time, commercial growers use nitric acid
(HNO3) to lower
pH in nutrient solutions.
Another acid used to lower pH is phosphoric acid (P2O5).
To prepare rock wool and to leach out the excess of nutrients during growth you
could also use monohydrate citric acid (wich is not the same as
Citric acid is never to be used in combination with nutrient
though (i.e. to lower pH), as it will form sludge in the container. Besides this
slime clogging your (eventual) drip-system, your plants can't cope with these
To rise pH you can use potassium oxide
Though acids and bases to lower and rise pH work full proof, they aren't 'fool
proof', so RTFM before you start experimenting. You should only
use a base or an acid, in other words: don't use base to get pH up, once you've
added to much acid.
Litmus paper can be used to determine the pH of your nutrient
To get to know the values you have to compare colors, which of course should be
done in natural (white) light. The modern meters do the same trick a lot easier,
and are already sold for as little as $80. If there is no grow-shop in your area
you can obtain one in a aquarium store. Remember that you also regularly need to
calibrate your meter to a fluid with a known pH (mostly 7.0).
7. Sexing Your
Once I heard a saying: "One fool can ask more
questions than a thousand wise men could ever answer", I don't know because
I'm not a wise man but I'm sure there is at least some truth in this.
But every once and a while I get a question that deserves a thorough answer,
though the question itself could be simple.
The inquiry above goes in this category. In fact I was so pleased with answering
this one that I decided to let the answer have it's own page, even if that means
the whole logical line of the course is going to smithereens. Who ever heard of
drying and curing your weed before you even grew it?
Well, I could always move the page to the back once I have the rest translated,
but let's not wait for that.
Now before we continue with the answer I hope I didn't offend anyone with the
saying. If I did I'm sorry, but I got one more:
"A fool who's foolish enough not to ask questions, will stay a fool for the
rest of his life." Having said that let's go on with the answer I gave
In my (humble) opinion, most weed is mistreated as far as
drying is concerned, while most growers don't even know the meaning of the word
Commercial growers take the colas from the plant and clean them before drying
(uh, did I really say clean?).
This drying takes place on (wire) netting and usually will be forced by the use
of extra heating. As soon as this weed is considered dry, it is sold. The reason
for this behavior is the fact they are, as said, commercial growers and in a
constant hurry to exchange their weed for money. Every minute counts plus they
don't want to 'waste' the space or the time needed for drying and curing.
That brings up the problem of space, as in 'room to
dry your plants properly' (I'll come to curing later).
Besides time, good drying takes its space because the best way to dry weed is by
hanging the whole plant upside down.
For the sake of quality I have to backtrack a
little, because curing already starts before harvest. Experienced growers will
give their plants only pure water, without nutrients, for the last week(s) of
its life. By doing so you force the plant to use the sugars and nutrients it has
collected in its leaves, the result being yellowish leaves and sweeter smoke.
Then comes harvest-time and basically all you have to do is cut the plant as low
as possible and hang it upside down to dry, use sharp scissors here like used in
rose-gardens. There are two problems with drying, and sometimes they conflict.
First and most obvious is the smell, which is
immense, especially for the first couple of days. There's no telling your
neighbors the cat peed in the bedroom, you have to either get the smell out or
keep it sealed in. Getting the smell out is quite simple, you dry the plants in
the same room used for growing them and leave the exhaust-fan running (you do
have a filter device there, don't you?).
Which brings us to the second problem:
air-humidity, which should not be too high because of the risk of molds and
should not be to low because you don't want your weed to dry too fast (you
really don't want that, you know). A lot of people also consider it a problem
that, obviously, you can't grow any new weed in this room while the old ones are
drying because drying takes place in the absence of (direct) light.
Well, enough of the problems, let's do some
positive thinking (uh, writing) here.
Live doesn't stop after you have cut down the plant, and I do mean the plant's
life here. All kinds of processes, like the transport of sugars inside the
plant, still take place. These processes will slowly come to an end while the
drying progresses, but are a main factor for the end-taste of your smoke. Now,
there's the first reason why you don't want to quick-dry your weed.
The second reason is the way a plant dries. Plants
are build up from cells and, as we all know, cells contain mainly water. Exposed
to air, the (dying) plant's outer cells will dry out first but the
above-mentioned processes will contiguously transfer water from the inner cells
to the dryer outer cells, thus causing the plant to dry equally all over.
If drying takes place too fast the outer cells will form an impermeable shield
around the plant, making it very hard for the inner cells to pass their water to
the atmosphere. The plant appears to be dry, but as soon it is packed it will
start 'sweating' and if you don't take action, mold is on it's way.
By far the best way to dry your weed is to build a
special room for it, which should not be much smaller than the room in which you
This room is completely sealed off from the rest of the world, so you keep the
smell in. Temperature and humidity have to be controlled and kept within the
range of 18° C and 60% (relative humidity).
In such a room the plant would be smokeable-dry in about six weeks, and you can
store (unclipped) plants there for years, curing it in the process.
Sadly but true, we do not live in a perfect world
and most of us neither have the space nor the resources to build such a room, so
(finally ;-) here's my advice to you.
Always give your plants pure water without any nutrients for at least the last
week before harvest, you could even go as far as three weeks but this takes a
lot of experience.
Cut whole plants; don't take off any of the leaves no matter what 'they' tell
you, and hang them upside down in the same room you grew them in. As long as
they are 'fresh' you hang them apart, i.e. don't have them touch each other,
once they get dryer you could hang them close together to slow the drying
Keep the exhaust-fan at the lowest level possible or use a timer to switch it on
for just as long as needed to keep the smell out of your house.
Should you have a 'problem' with new clones arriving too soon, at least dry your
plants in the growing room for the first three days, after that you could
transfer them to a bed- or bathroom for the rest of the drying-process. Most,
but not all, of the smell will be gone after three days so you could ease on
ventilation, but take care, after two or three days you get used to the aroma
but that doesn't mean there's no smell left!
Probably you won't need as long as six weeks to
dry; most weed is clip- and smoke-dry after about three till four weeks and now
there's two things you could do.
If humidity is around 60% and temperature is around 18º C, you leave them
hanging there, without cleaning and touching (no lights, mind you).
Or, like most of us do, you clip (clean) all the buds and pack them airtight to
keep the oxygen from doing its destructive thing.
You could use buckets with an airtight lid like used for food and sauces and
such, just put as much weed in it as possible using a light pressure. For safety
sake you check the next day if the weed is still dry, i.e. it didn't sweat. When
it's moist (soft) you leave the lid open or, better, spread the weed on a
newspaper on a dry place to get the last water out. After the weed is completely
dry you close the lid, pressing out as much air as possible, and place the
bucket in a cool room.
A vacuum-sealing machine is also a good thing to pack weed, apart from the fact
they are very expensive. Use only a light vacuum, you don't want to press the
weed but just want to get the air out.
Curing is actually a form of
fermentation and takes place by itself. Just store the weed and it will get
better and better.
By curing your weed the taste of the smoke will be sweeter, and the high will be
mellower, contrary to the flashy but shorter high of fresh weed.
Besides that, if you are not a commercial grower but grow your own, you need to
stash to keep yourself supplied until next harvest.
Main factors for storing (dry) weed are temperature, air, and light.
- As far as temperature is concerned, THC gets
destroyed at higher temps, but the most important thing is to keep the
temperature at a constant level. Storing at a constant temperature of 20º
C., though not perfect, seems to be better then storing in a cooler place
where temperature jumps up and down.
- The oxygen in air will destroy THC, which will
happen at a faster rate once you cleaned the buds. This is mainly because,
while clipping, you damage the THC crystals and the reason you have to pack
clean weed airtight, the plants you didn't clean are protected by the
leaves. Try to keep buckets full, once you start smoking you pack the weed
in smaller buckets or use Tupperware. Zip-bags are totally unfit to store
weed for a longer period of time because they're not airtight.
- Light is easy, keep everything in a dark room or
at least out of direct light (that's in the shade).
A very nice place to store weed is the
refrigerator, the only problem would be humidity which is too high so pack
You could even deep-freeze your weed and keep it for ages, but the curing would
stop. (A word of warning: Leave the weed in its packing until it reaches room
temperature or it dries out completely.)
To add it all up: You don't want your weed to dry
too quickly, but whatever you do, don't spray water to slow the process.
If the drying room is too dry you could simply place some buckets or bowls
filled with water there to raise humidity, but again, don't spray water.
To store it, weed needs to be 'crisp-dry'; it feels hard and will easily break
and crumble but you don't want it to fall apart at first touch so don't overdo
things as in drying. Dry it, clip it, store it, check it, and check it again,
the result is worth it.
9. Seeds and Cuttings
Up till here I wrote about how to make a nice
environment for your plants without getting the attention you don't need.
I think it's about time I started telling you boys and girls how to grow weed.
Although I grow Haze, which is a long blooming plant, the basic principles go
for any weed-plant, so even if you grow Skunk or the likes you could still find
some things of interest here.
Man, I think you could even grow tomatoes if you follow my description.
As it seems to be my normal way to tell things I'll start at the end of our
Weed does not grow for our satisfaction (alone ;-), it grows to multiply
itself and Mother Nature's way of multiplying weed-plants is by letting it grow
seed. One female plant can produce thousands of seeds. Those seeds fall on the
ground or are eaten by birds, and maybe a couple of them will land in 'rich
soil' where they'll take care of the next generation of plants.
Outdoors the new life enclosed in these little seeds has to wait until the time
is right to start growing.
The plant will start its life in springtime when days are getting longer, and
Cannabis is what we call a short day plant. This means it will flower when
the days are getting shorter. As a matter of fact, weed requires twelve hours of
light and twelve hours of absolute darkness to bloom. And again I emphasize the
importance of absolute darkness here.
What happens is that the plant produces a hormone (called phytochrome) that
controls - amongst many other things - the growing and blooming of the plant.
Though this hormone is being produced day and night, it is disintegrated by
light and will not trigger blooming while days are long. In fall, when days get
shorter and nights get longer, this hormone will not be broken down as much
anymore and blooming will occur.
Once people found out that it is the length of day and night - called
photoperiod - that is responsible for the blooming of certain plants, they
started to experiment. Probably all of you know the example of the Christmas
cacti, or Christmas rose that is grown under special light conditions so it will
bloom around Christmas Eve.
There is not much difference with the conditions weed is grown indoors. An
expert grower can flower his or her plants at will, just by shortening the days
to twelve hours.
Keep your plants under eighteen hours of light per day, and they will never
This gives us a very interesting opportunity because it means that you can
take a plant, of which you are sure that it's a female of good quality, and keep
this plant in a vegetative stage. This one plant could provide you with cuttings
for a very long time, so you would always know in advance what you were growing.
Although in nature cannabis is one-year plant, I know of so called 'Motherplants'
that live already for fifteen years or more and still provide excellent
Off course one has to refresh this plant after a while with a nice looking
cutting of it's own, but a cutting of a plant is always a one to one copy of
it's originator. All the DNA of the original plant is in the cutting.
If you take care of the ladies well, so they won't catch any diseases, you could
go on forever with just one plant (well, 4ever is a very long time, but I think
you catch my drift ;-). After twenty years, it could still be as potent as if it
were twenty weeks old.
And this, my dear friends, is what we call a mother-plant.
Off course we first need a plant, and since most of us start with seed, let's
Seeds are best to be germinated in a warm, moist place. Place the seed on wet
cotton wool until it germinates. Also it's best to keep them in the dark until
you see the tip of the root breaking through the seed's coating.
You could even give it a little help after a short week by gently squeezing the
seed's side rim till it knacks open. Of course this is a trick that could lead
to disaster so play it safe and let nature have its course.
Once sprouting, you have to provide a place for the little root to grow in. this
could be earth of course, but if you plan to grow hydroponics you might as well
start now by placing it in a small rock wool cube
TIP: Even if you plan to grow on dirt, you could still grow your seed (or
cutting) in rock wool and place the whole bunch (including wool) in a cannabis of
The little plant needs light, eighteen hours per day is a rule of thumb.
Though some people will give you the advice to place mothers, seedlings, and
cuttings under twenty-four hours of light per day to prevent blooming, I am not
in favor of that practice. I found out that the total absence of a dark period
causes a lot of stress to plants. Eighteen hours of light and six hours of
darkness will still keep your plants in a vegetative state and give them some
time to rest and catch up.
Once your little seedling gets a few leaves with 'fingers' it's starting to
look like a little plant.
Because after this stage the treatment of seedlings is basically the same as the
treatment of cuttings, I suggest we discuss cuttings now and proceed with the
Cuttings or clones
Although clones seems to be a normal word for cuttings in the US of A, people
in Europe think of sheep, called Dolly, hearing this word. That is why I will
use the word cuttings instead.
Most people (in Holland) buy cuttings to flower. Even if you don't plan to
change this line of working it makes sense to know how they are grown, so read
A cutting is just what the word says; it's a piece of branch that's cut off
from the original (mother-) plant.
Let's have a look at a full-grown weed plant; you'll see that it's a stem with
side branches, opposite pairs to the bottom, which shed along while going to the
top. These side branches grow other branches, which hold up smaller branches,
supporting... uh well, I think you'll get the picture.
Now have a look at the smaller branches and again there's the pattern. Leaves
start in pairs while further down they separate. In the axis of these leaves
with the branch (called node) you will see the premature start of yet another
branch. The peaces of branch in between two (sets of) leaves are called
It is the last two till five inches of these branches you want as a cutting, but
hold your horses, there's more to it than just cutting them of.
- First of all you only use very clean tools when you're working on your
plants because you don't want to infect them with some weird disease.
You'll need a sharp pair of scissors, preferably a small and pointed one.
Besides that you need a really sharp knife.
For the latter I always use the old fashioned 'safety razor blades',
they are sharp as red chili pepper and cheap.
After using them for a while I toss them away for hygienic reasons.
You also might want to use a mild rooting agent, though I never noticed the
- Second you do not want the mother to die in favor of the babies (if you
do, just skip this section).
- Third you want to have more cuttings in the (near) future, and believe me,
these cuttings could do better then the first you take.
So let's do it.
Your fresh cutting will have a hard time to survive the first week, so you
have to help it a little.
Cells that used to be part of a branch suddenly have to adjust to life under the
ground and they have to develop roots. Certainly a difficult job, but don't
worry as weed is an cannabis and a strong one too.
Like I said, there's new growth in the joint of leave and stem, so you want to
save that on the mother plant. On the other hand there's the fact that cuttings
do better if you leave this node on, so we have to plan a little.
First you have to decide how long you want your cutting to be. If you cut a
somewhat bigger plant you could bloom it (a little bit) earlier, but it's also
harder to keep alive.
The most important thing however is that all of your cuttings are about the same
Normally I always use my index-finger as a ruler. The cutting will be
about as long as it, and the 'end joint' (of my finger ;-) goes under the ground
Another thing you have to think of is that every single cutting needs at
least one full-grown leave, i.e. with five fingers, though you might want to cut
it in half (later). This leave is needed to give the plant nutrients for the
first week(s) of it's life; it will probably turn yellow/brown and fall off
later so don't worry and write me about that ;-)
Take a nicely grown branch and decide which node you want to be the foot
of your new plant. With the scissors you cut the stem just above the previous
node from this branch.
You will now have a cutting that's a bit too long, and (most
likely) has too many leaves to survive.
The cells in the leaves will still evaporate water, but the little plant has no
roots. To minimize evaporation you have to cut of most, but not all
of the leaves. Also all of the growth that's on the last node (your 'rooting'
point) has to go.
To 'clean up' the cutting you use the razor blade, and the last thing you do is
to cut the stem, just below the node, in a 45 degrees angle.
How much leaf you leave behind depends on how big you make the cutting.
More is better, but harder to keep alive.
I would say the minimum you need is one square inch of leave on a cutting of
about 1.5 inch long.
If you root your cuttings in rock wool (which you have prepared beforehand by
soaking them in water) you place the fresh cutting in the cube right away.
After you're done with all of the cuttings you fill the tray which hold the rock
wool cubes with as much water as needed so all the cuttings will have their feet
If you root in soil, you place them about an inch deep in a glass of water for a
night so they have a chance to fill themselves up after which you place them in
the soil the next day. Besides giving the cuttings something to drink, standing
in water for a night seems to be good to get rid of unwanted debris.
Do not give these plants any direct light right away; it's okay to leave the
lights of for the first night. Sometimes I forget, and they won't get light for
a day, but it doesn't seem to bother them.
The next morning you have to throw away the water they stood in, and of course
the earth people have to plant the cuttings in dirt. After doing so you place
the cuttings under eighteen hours of light, and that's basically it, let nature
do it's thing.
It's very important that, from this day on, you keep the growing medium
moist, but not soaking wet! This really could mean the difference since the new
roots need oxygen to form, and water is a real bad transmitter for gasses.
Besides light, seedlings and cuttings need warmth. Best thing is to keep
temperatures at a minimum of 20° C, but this might be as high as 25° C and I
do mean root temperature here!
Only after enough roots have been formed, you start with giving a very
mild nutrient-solution. I would say 10 - 15 % of the 'normal' strength is good
enough for starters. If you grow on soil you only give water because there's
plenty of nutrients available there for your plant to get it through the first
A word of warning! Contrary to animals, plants do not get
'fatter' by giving them more food. In fact they will die, mostly on dehydration
because of Nitrogen poisoning.
Photoperiod: (photo = light, periodicity = recurring
regularly) The relation between light and dark.
Node: Where the leave grows from a branch.
Internode: The stem between two nodes.
Growing (or rooting) medium: That in which the plants root.
In nature this would be the earth. In hydroponics it could be rock wool.
GROWING GUIDE FOR HAZE