Introduction to co2....

Discussion in 'Advanced Techniques' started by Native¥organicfarmer, Mar 4, 2012.

  1. Native¥organicfarmer

    Native¥organicfarmer Registered+

    Photosynthesis briefly,

    chlorophyll pigments absorb light and convert it to electro-chemical energy.
    This energy used to cleave water and combine the H with co2 to form sugar and release oxygen.

    Plants gather energy from light using chlorophyll located underneath the leaves. stoma small pore like openings found mostly on the underside of the leaves intake co2 and release oxygen, all at the same time. Furthermore the roots absorb water and newts from the planting medium. the stored energy is use to split water molecules h2o. the oxygen o2 is released as gas. the hydrogen atoms combine with water to make starch, which is converted into sugars,
    the entire process is called photosynthesis.
    then the sugar is used to fuel metabolisim as a building block for amino acids which are turned into proteins that are used for growth. (just like humans)

    6(h2o)+6(co2)+light=> 6c12h60+60 = .001

    water,carbon dioxide,lumens

    What that means is 1 pound of c02 consumes 8.7 cubic feet

    You can calculate how much co2 is needed to bring a growing aera to 1000ppm (which is optimal) by
    multiplying the cubic area of the growing room (length x width x height) by .001.
    The total goal number represents the the number of square feet of gas requires to reach an optimal
    level of co2 available in your grow room environment.

    For instance my old grow room:

    13x18x12 contains 2808 cubic feet
    so 2808 x .001=2.8 cubic feet of co2 required to grow
    optimally with all environmental issues in place and dialed in.

    so in short a room 3x3x4 requires .36 co2

    Effect on temperature on photosynthesis. As the amount of light increasing past 56,000 lumens per sq foot one foot from dry 1k light the plants can utilize the extra energy fully only when the concentration of co2 in the air increases. However, as light and co2 concentrations increase the plants metabolic rate is regulated by temperature.

    In this light and co2 levels are constant and should be maintained. (closed grow-room easy flow through more complicated)
    Photosynthesis and the metabolisim of the plant increase with the temperature.
    As the temp rises from 50deg to 90deg (40deg bounce) at the leaf surface photosynthesis increases by a factor of 5
    from 70-90 deg (20deg bounce) it increases even more 2.5 with all environmental elements in place.
    With a total of 7.5 rate increase. NOTE temp is measured at surface, not ambient air temp....

    Co2 TEMPERATURE AND LIGHT--- co2 usage and photosynthesis are effected by temperature. Plants received three uniform temperature regimes
    50-70 had more co2 than they could use and newts room ran at 600ppm
    70-85 also had more co2 than they could use at 1000ppm
    80-90 used nearly twice the co2 and made huge harvest. almost 50%..... (strain DE-pendant)

    Plants grow heavier and faster when supplemented with co2. raising the level of co2 up to 0.15% 1500ppm or a little more than 4 times the amount of co2 in the outdoors, thus increasing plant growth indoors using co2 either by fresh air or co2 introduction.

    Here are some basics,

    when plants in an enclosed area, their is a limited amount of co2 for them to use. under bright lights 1,000k plus, co2 is used up very quickly.....
    Enclosed gardens with little or no ventilation are at the worst with co2 and environmental elements depleting and generally not replenished to the point where the photosynthesis slows to a virtual STOP. (around 200ppm). Only when co2 is added to the environmental can the plant resume photosynthesis.

    A small closet or room can be recharged with co2 by opening a door or introducing a air flow via fan from outside. This incresses the co2 value in the room passively not positively (my grow room)

    The slowest rate of photosynthesis is 200ppm under low light conditions 10,000 lumens, the photosynthesis rate increases at around 400ppm while increasing co2 concentration beyond that, without increasing light intensity does nothing it does not increase the photosynthesis rate any higher.


    At a light increase of 300,000 lumens the photosynthesis rates increase more as the co2 concentrations increase to 600ppm, above 600ppm of co2 the rate of photosynthesis climbs, but even at a slower rate as before until co2 concentrations reach 1000ppm.

    By increasing your co2 and all environmental elements you can make your plant absorb more co2 and newts thus increasing growth and yield.
    when plants receive around 60,000 lumens per square foot they can utilize 1200-1500ppm of co2.

    Very few gardens are equipped with such powerful indoor lighting or the technology to supply plants with co2 but their are many ways to do this,
    you can supply your garden easily and cheaply just but providing fresh air to your garden......

    Hope it helps......

    Dam time to medicate......
    2 people like this.
  2. Native¥organicfarmer

    Native¥organicfarmer Registered+


    Almost all living beings are dependent on light of satisfactory quality. For humans, that means that sufficient oxygen must be present in the air, and that the air is not too polluted. For plants, and thus also for cannabis, it means good air quality, enough carbon dioxide (CO2), and not to much pollution. Relative humidity (RH), and temperature also play a large role in the growth of plants.

    Influencing air quality

    The amount of CO2 in the open air is approximately 0.03 to 0.04%. The amount of carbon dioxide is also expressed in parts per million; ppm. 0.03% is equal to 300 ppm. There are differences in the CO2 needs among plants. By raising the CO2 content, growth can be accelerated. The law of diminished returns still holds true, however. Raising the CO2 level has limits, but at approximately 1400 ppm (0.14%), good results (a faster growth) are generally achieved. Above 1400 ppm, the effect of a higher percentage of CO2 decreases. A high concentration of CO2 is poisonous even for plants. A CO2 concentration of 1800 ppm or more is deadly for most plants.
    A simple method for guaranteeing the supply of carbon dioxide is to ventilate the room. Sufficient ventilation must be provided, so the plants keep getting enough fresh CO2.
    A second and just as important reason for ventilation is to dispose of excess heat. If the temperature gets too high, growth is stunted. This counts not only for the temperature in the grow room, but also for the temperature in the plant itself. When the plant's temperature is too high (humans get a fever), there is less sap flow, causing growth disturbances. There is no standard solution for refreshing the air. The need for fresh air is, for a large part, dependent on the size of the grow room in cubic metres. In principal, the total air content of the room must be exchanged every 2-3 every minute. Using for example a grow room 3 meters long, 2 metres wide, and 2 metres high (12m³), this means that the ventilator capacity must amount to 30 x 12 = 360 m³ per hour. A standard bathroom ventilator can only handle up to 100 m³ per hour. Many growers ventilate their rooms with table fans. The point is the control of the temperature as well as the circulation of the air with sufficient carbon dioxide. Table fans are primarily intended to keep people comfortable on a hot summer day. They are much less suited to run continually for heat removal, and for CO2-content maintenance. Table fans have a tendency to melt with intensive use. You can imagine the consequences: not only the danger of fire, but also massive plant death. There are, of course, plenty of fans on the market which will take care of proper ventilation. These have been specifically designed to be able to run continually.
    The CO2 content in the grow room can also be heightened by adding CO2 from a tank. If the system is set with a timer clock, the desired amount of CO2 can be regularly released. Work with care, because you don't know how much CO2 is in the room at any given moment. An overdose can easily occur. To prevent this, it's sensible to ventilate the area well before each CO2 'injection'. The most professional option is to use a CO2 controller. This apparatus continually measures the CO2 content in the room. When the programmed minimum value is reached, CO2 is automatically added. If the programmed maximum is exceeded, the controller turns on the ventilating system. If CO2 is added to the room via a tank, or a controller, cultivation can take place at a higher temperature.

    Ultimately, attention must be given to the relationship between ventilation, and the relative air humidity. The humidity of the air is dependent, among other things, on the amount of air moved through the room. Changing the air draws more moisture out of the plants, because the stomata release more moisture. If the relative humidity of the air drops too low, the stomata close, delaying the growth process.

    Relative humidity

    The relative humidity of the air influences the functioning of the stomata, among other things. Cannabis flourishes the best with an RH of 60-70%. At higher RH percentages, the stomata have problems getting rid of excess water. At a lower RH, the stoma keep releasing water until the plant dries out. At that moment, the stomata close. Then, the intake of CO2 stagnates, and plant growth is impaired. The relative air humidity is also influenced by the temperature in the growing space. In the chart below, you can see the number of grams of water which can be absorbed in a 25 m³ room (for example: 3 x 3 meters, and 2.5 meters high).

    Absorption in grams of water (degrees C): - 0 degrees 120
    - 10 degrees 240
    - 20 degrees 460
    - 25 degrees 630
    - 30 degrees 840
    - 35 degrees 1120
    - 40 degrees 1460

    It may be concluded from this chart, that with every rise of 10 degrees in temperature, the air humidity doubles. Ventilation influences the relative humidity. Ventilating a space makes the RH fall. In some cases it's necessary to install a humidifier in the grow room. The best results can be achieved by using a discharge fan with a variable speed control. This way, you can easily regulate the quantity of air to be removed. When the plants are in the dark, the temperature is lower (the lamps don't give off any heat). So, you would expect the relative humidity to fall (less moisture can be absorbed by the air). But this is not the case; RH increases in the dark. The plants breathe out water in darkness. Therefore, sufficient ventilation must be provided. Too high a humidity level provides considerable risks for the health of the plants. Generally, pests and diseases have a better chance with a high humidity level. Too low an RH is also risky; the plants can easily dry out. Prevention is better than cure.

    Finally, it should be stated that young seedlings and clones generally perform better at a humidity level of 65-70%. Their root systems are not yet developed well enough to take in water fast enough. A higher humidity insures that the young plants will be protected from drying out.

    The high-pressure gas lamps we use for cultivation cause a considerable amount of heat in our closed-off grow space. This heat can be damaging to the plants. In the first place, we have to make sure the plants are not too close to the lamps. A distance of approximately 40 centimetres (for 400 Watt lamps), or 50 centimetres (for 600 Watt lamps) is good.

    Lamp height

    The lamps also warm the air in the room. This heat must be discharged via the ventilation system. Cannabis seems to grow best at a temperature of 25 to 26 degrees Celsius. This temperature must not be allowed to rise any higher in grow rooms where no CO2 enrichment takes place. When working with bottled CO2, or even a CO2 controller, the temperature can be a little higher; 27 to 29 degrees. When working at higher temperatures, the RH must be closely monitored. Every 10 degree rise in temperature means that the absorption capacity of the air nearly doubles (see Section 4.3). In the dark period, the temperature may drop a little, but not too much. If the temperature is too low during the dark period, moulds have a better chance. A temperature of approximately 20 degrees Celsius is ideal for darkness. In order to maintain an optimal temperature, you need a discharge ventilator. The discharge ventilator has a double function: refreshing the air, and drawing off the heat. As described earlier, the capacity has to be great enough to replenish the air content of the grow room at least 30 times every hour. Accordingly, when working at higher temperatures (by adding CO2), the plant needs more water and more feeding. Remember the law of minimums. We can raise the CO2 supply, but if we don't give extra water and extra fertilizer, plant growth adapts itself to the aspect of poor care.
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  3. Native¥organicfarmer

    Native¥organicfarmer Registered+


    Plant growth involves the conversion of light energy into plant-building materials. Two factors are important for optimal growth. In the first place, the light intensity. Light intensity is expressed in 'lumens'. At least 50,000 lumens are needed for growing indoors. It's not sufficient to add up the number of lumens listed by the manufacturer for each lamp. The total number of lumens given off is depends strongly upon good reflection, and proper connecting fixtures and starter ballasts for the lamps and the draw your pulling at operating temp. The quality of the reflector used, and the connecting fixtures and ballasts determine the light yield for the greatest extent. For those reasons, self-built sets and home-designed illumination often deliver a lot less light yield than lamps being used in professional horticulture. We can improve the light yield in our grow room by applying reflective material. We haven't painted the walls of the room matt white, and used reflector caps for the lamps for nothing! The second important factor is the wavelength of the light. For the production of chlorophyll, and an optimum photosynthetic reaction, light from the blue spectrum (445 nanometres), and light from the red spectrum (650 nanometres) is necessary. Blue light ensures optimal phototropism. Phototropism is the phenomenon which causes plants to grow towards the light, and to spread their leaves in such a way to receive the most light.

    Choices for lamps

    In this we prefer high-pressure sodium lamps, and mercury-iodide lamps for illumination. Ordinary light bulbs are not suited for cannabis-growing due to their considerably short life span, and principally due to their low light yield. Halogen lamps are not advisable for the same reasons. Fluorescent lamps are not appropriate for home growing nor the use of LED is advised. They do serve well, however, to stimulate seedlings and cuttings to set root. For actual growing, we stick to gas discharge lamps in the form of high-pressure- sodium, and mercury-iodide lamps with the use of t5 for veg growth. There are lamps being sold which emit both the wavelengths needed (blue and red) but we prefer installing separate lamps in a 1:3 proportion (1 lamp for blue light with 3 for red light). The combination lamps give off a lower amount of lumens, since they have to emit different wavelengths. This counts for growing: the more lumens, the greater the yield. This doesn't mean we can install an unlimited number of lamps. Other factors must be considered. Using many lamps means a higher temperature (the heat must be discharged off), a greater need for fresh air (containing CO2), and a greater need for water and feeding. Always remember the law of minimums. Depending on the size of the garden, use 400 Watt lamps or 600 Watt lamps. This choice is made in such a way that all the plants in the garden area can be illuminated as evenly as possible. By using 400 W lamps, you can put up one-and-a-half times as many lamps for the same electricity use as when using 600 watt lamps. Also 1000 watt lamps are being sold but proper reflectors for these types of lamps are not widely used or operated at 220 to reduce cost. (Parabolic) provides a larger more even foot print rather than penetrating type hoods.
    In practice, it is possible to reach a light yield of 70-90% of the lumens which are emitted. For that, (it can't be stressed enough), good reflection is necessary.

    Below is a chart with data for several reflective materials:

    Reflectivity in %
    - Reflective plastic sheet 90-95
    - Matt white paint 85-90
    - Semi-matt white paint 75-80
    - Matt yellow paint 70-80
    - Aluminium foil 70-75
    - Black paint less than 10

    Using proper reflective material, proper connecting fixtures ballast equipment, proper reflector caps with the lamps, and a distance from the lamps to the plants of 40 to 60 centimetres, 400 Watt lamps deliver, on average, between 35,000 and 47,500 lumens, and 600 Watt lamps between 60,000 and 80,000 lumens (at a distance of 50-70 centimetres). The distance between the plants and the lamps differs because 600 W lamps give off more heat. If the plants are to close to the lamps, they will dry out and burn. 600 Watt lamps are preferred, because you get the highest light yield for the lowest electricity cost. Though they do require more careful climate control. The life span of a high-pressure gas lamp is approximately 2 years when it's used 18 hours a day. The lamps are, however, subject to decay, which lessens the light yield.

    In practice, it appears that high-pressure gas lamps give optimal results for 4 to 5 harvests. After those, it's advisable to replace them. It seems that the installation of one 600 Watt sodium lamp per square meter is enough to achieve the best results. (but we use 1000k) Principally one can say 'the more light, the better', but with more illumination, the control of other factors (namely, temperature control) becomes a problem. Indoor growers work with their light source close to the plants. Considering the light yield of the sun, (hundreds of thousands of lumens, but a little further away), fewer lumens are needed for growing indoors. A simple formula shows that you can also use three 400 W lamps for 2m². The sodium lamps provide light from the red spectrum. This light is used principally during growth. A mercury-iodide lamp fills in the blue spectrum. For reflection, growers use wide-angle reflectors with sodium lamps, and super-wide-angle reflectors with mercury-iodide lamps. Super-wide-angle reflectors spread the light over a greater surface area. We use the proportions of 3 red lights to 1 blue. So, the light from the blue lamp must be spread over a larger surface area.

    Using high-pressure gas lamps

    High-pressure gas lamps may only be used in the fitting meant for that particular lamp type. High-pressure gas lamps all have their own start-up conditions, voltages, characteristics, and shapes. Using lamps with improper sockets can cause electrical shorts! Therefore, it's recommended that you buy all the parts of a pressurized gas lamp from the same distributor. The sockets, ballasts, and connectors must always be protected from humidity; otherwise, electrical shorts occur. As stated earlier, high-pressure gas lamps have a long life span. You must be careful when replacing these lamps. They are, as the name implies, under pressure, and they explode when you destroy them. When you do that yourself, you must always wear gloves and safety glasses. In addition, you have to protect yourself against the poisonous materials found in these kinds of lamps.

    The use of gloves to protect the light bulb

    The heat given off by high-pressure gas lamps, and their accompanying starter ballasts, must be completely ventilated. This means that the lamps shouldn't hang too close to the plants (hence drying and burning occurs), but also not too close to (flammable) ceilings and walls. Place a piece of non-flammable material (not asbestos!) between the lamp and ceiling or wall. Furthermore it's necessary to discharge of excess heat by using a ventilator. Finally, it's important to keep high-pressure gas lamps clean. Dirty lamps provide much less light yield than clean ones. The lamps should be polished now and then with some glass-cleaning agent. That should be done only when the lamps are turned off, and well-cooled.

    Proper lighting for cannabis

    The advantage of growing cannabis indoors is the fact that you can give the plants the feeling that it's their flowering season all year round. You're not dependent on the weather or the season.
    We distinguish 2 separate phases in plant cultivation: the growth- or vegetative phase, and the flowering- or generative phase. We've already made sure the lamps are installed in such a way that all the plants can be optimally illuminated. A light period of 18 hours and a dark period of 6 hours are ideal for the vegetative phase. We're assuming that you already have cuttings with roots. With proper care, a healthy cannabis plant can grow up to 5 centimetres per day. It's very easy to cause the plant to flower. We only have to give the plants the idea that the days are getting shorter ('autumn'; for cannabis, the sign to flower). We do that by making the light and the dark periods the same length; - 12 hours. In principle, cannabis is an annual plant. The entire life cycle, from seed to death, takes place in one year in nature. When growing cannabis under artificial light, it is possible to force flowering earlier than in nature. After 4 or 5 days vegetative phase, (30 days suggested but 2 weeks optimal for plant height) flowering can be 'provoked'. We do that the moment the clones have visibly started to grow. Two or three weeks after the light period is reduced to 12 hours, the plants begin to flower. It's very important not to interrupt the dark period. If the plants receive light during the 12-hour dark period, they 'get confused'; they want to continue growing, and the blooming phase is postponed. The generative phase lasts 60 days or longer, depending on the variety you're growing. When working with cuttings, it's possible to harvest every two weeks

    Think i overloaded my brain.....

    so dam hard to remember everything nowadays.......
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  4. Baby

    Baby Registered

    Just wanted to say thank you for your post.. you answered alot of questions i had.. but just wasnt smart enought to brake down on my own... :)
  5. pipesdaddy

    pipesdaddy Registered+

    You have clarified many things. Thanks for the post.

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