DIY-HP-LED
Well-Known Member
Economical CO2 Monitoring And Enrichment For Small Grows
For those who use high intensity light on their grow like me and who have all the other bases covered, like roots, nuits and environment. This might be a viable option for a small grow, when used to tweak a small methanol burning lamp to get the CO2 levels to 1000- 1400 ppm range. A 10%-20% gain on a one pound plant would make it more than worth it, use up that extra light and turn it into bud. Think about it like this: the only way the plant absorbs carbon is through the air and since the great majority of the weight at harvest is in bud, the plant puts that weight on during flowering. So CO2 has to be useful during more than just veg and early flower.
CO2Meter RAD-0301 Mini CO2 Monitor, White $70. US plus $12 US Shipping
http://www.ebay.com/itm/222616155745
Here is some text on the subject from page 12 of this thread.
With water cooling it should be possible to have a sealed grow room or dramatically reduce the air flow through the room. The high power densities possible with water cooling make it easy to max out on light levels, especially in small spaces. This opens up the possibility of CO2 enrichment of the grow and the benefits it provides. Most small growers aren't going to buy an expensive rig to monitor and supplement CO2 or want to buy or rent gas bottles. Burning a couple of ounces of methyl alcohol in a small lamp will provide double or more the CO2 than is in ambient air (300 ppm). A cheap ebay CO2 monitor can fine tune things and help with the adjustment of the burning rate until you get close enough to the levels you want.
Here is some text from another website
https://www.hydrofarm.com/resources/articles/co2_enrichment.php
"We will discuss these five methods briefly in turn. In order to make an effective comparison of CO2 generation, benefits and drawbacks, a std. 8' X 8' X 8' or 512 cu. ft. growing area will be used.
1. BURNING HYDROCARBON FUELS:
This has been the most common method of CO2 enrichment for many years. A number of commercial growers and greenhouses use it in their larger structures. The most common fuels are propane, butane, alcohol and natural gas. Any of these fuels that burn with a blue, white or colorless flame will produce carbon dioxide, which is beneficial. If a red, orange or yellow flame is present, carbon monoxide is being generated due to incomplete combustion. Carbon monoxide is deadly to both plants and people in any but the smallest quantities. Fuels containing sulfur or sulfur compounds should not be used, as they produce by-products which are harmful.
Most commercial CO2 generators that burn these fuels are too large for small greenhouse or indoor grow room applications. Some small ones are avai fable or a Coleman lantern, bunsen burner or small gas stove can be used. All of these CO2 generators produce heat as a by-product of CO2 generation, which is rarely needed in a controlled environment grow room but may prove beneficial in winter growing and cool area greenhouses.
The rate of CO2 production is controlled by the rate at which fuel is being burned. In a gas burning CO2 generator using propane, butane or natural gas, one pound of fuel produces approximately 3 pounds of carbon dioxide gas and about 1.5 pounds of water vapor. Approximately 22,000 BTUs of heat is also added. These figures can vary if other fuels are used.
To relate this to our standard example in an 8' X 8' X 8' growing area, if you used ethyl or methyl alcohol in a gas lamp or burner at the rate of 1.3 oz. per day, we would enhance the atmospheric concentration of CO2 to 1300 PPM if the room was completely sealed.
An enrichment standard of 1300 PPM was chosen as it is assumed that 1500 PPM is ideal, and that the plants will deplete the available CO2 supply by 100 PPM per hour. Remember, the normal atmosphere contains 300 PPM of CO2. A 100% air exchange (leakage) every two hours is assumed to be the average air exchange rate in most grow rooms and tight greenhouses. If many cracks and leaks are present, this exchange rate will increase significantly, but added CO2 (above 300 PPM) will also be lost. If a vent fan is in use, disregard CO enrichment, as it will be blown out as fast as it is generated.
A circulation fan is beneficial, as it moves the air about in the greenhouse or grow room. If the air is still, it can cause a "depletion layer effect". This effect causes the CO2 right next to the plant leaf to be quickly depleted. If fresh air carrying additional CO is not brought to this surface, photosynthesis and growth will diminish and eventually cease.
There are a number of factors involved in keeping the CO2 content at the desired concentration level. 1. If the greenhouse or grow room is not tightly sealed up, add up to 50% to the CO2 generator production volume. 2. If temperature is increased fiom 70 F to 90 F, add 20% to the volume generated, and vice-versa. 3. If the grow area contains large or tightly spaced plants, add 20% to 30% to the CO2 volume generated.
If more light is used, more CO2 can be utilized and should be produced proportionately up to the practical limit of 5,000 footcandles per square yard and 1500 PPM CO2 atm. content. When more CO is generated, more water and plant nutrients should be used, again to a practical limit of 2X normal. lf your plants are going to grow faster because of CO2 enrichment, they will need more nutrient and water.
The last factor to consider in maintaining a set CO2 level is the size of your growing area. This is simply done for gas burning and following methods by setting up a mathematical ratio. In our "standard" room (8' X 8' X 8'), we have 512 cubic feet. If your growing area measures 10' X 10' X 20', you have 2,000 cubic feet of volume to contend with. If you want to use the ethyl alcohol/gas-lamp enrichment method, set up the ratio using l.3 oz. by weight of alcohol per day gives:
1.3 oz./day = 512 cu. ft.
------------------ -------------------
X oz./day = 2,000 cu. ft.
Then cross multiply: 512 X = 1.3 X 2,000. Dividing both sides by 512 gives you X = (1.3 X 2000)/512, solve for X. X = 5 oz.
You need 5 oz. of ethyl alcohol per day in a 10' X 10' X 20' grow area to generate the same amount (1300 PPM) of CO2 as in a 512 cu. ft. room.
To generate 1500 PPM above the available CO2 (200 PPM) in the same size area, set up the ratio:
1300 PPM = 5 ounces"
For those who use high intensity light on their grow like me and who have all the other bases covered, like roots, nuits and environment. This might be a viable option for a small grow, when used to tweak a small methanol burning lamp to get the CO2 levels to 1000- 1400 ppm range. A 10%-20% gain on a one pound plant would make it more than worth it, use up that extra light and turn it into bud. Think about it like this: the only way the plant absorbs carbon is through the air and since the great majority of the weight at harvest is in bud, the plant puts that weight on during flowering. So CO2 has to be useful during more than just veg and early flower.
CO2Meter RAD-0301 Mini CO2 Monitor, White $70. US plus $12 US Shipping
http://www.ebay.com/itm/222616155745
Here is some text on the subject from page 12 of this thread.
With water cooling it should be possible to have a sealed grow room or dramatically reduce the air flow through the room. The high power densities possible with water cooling make it easy to max out on light levels, especially in small spaces. This opens up the possibility of CO2 enrichment of the grow and the benefits it provides. Most small growers aren't going to buy an expensive rig to monitor and supplement CO2 or want to buy or rent gas bottles. Burning a couple of ounces of methyl alcohol in a small lamp will provide double or more the CO2 than is in ambient air (300 ppm). A cheap ebay CO2 monitor can fine tune things and help with the adjustment of the burning rate until you get close enough to the levels you want.
Here is some text from another website
https://www.hydrofarm.com/resources/articles/co2_enrichment.php
"We will discuss these five methods briefly in turn. In order to make an effective comparison of CO2 generation, benefits and drawbacks, a std. 8' X 8' X 8' or 512 cu. ft. growing area will be used.
1. BURNING HYDROCARBON FUELS:
This has been the most common method of CO2 enrichment for many years. A number of commercial growers and greenhouses use it in their larger structures. The most common fuels are propane, butane, alcohol and natural gas. Any of these fuels that burn with a blue, white or colorless flame will produce carbon dioxide, which is beneficial. If a red, orange or yellow flame is present, carbon monoxide is being generated due to incomplete combustion. Carbon monoxide is deadly to both plants and people in any but the smallest quantities. Fuels containing sulfur or sulfur compounds should not be used, as they produce by-products which are harmful.
Most commercial CO2 generators that burn these fuels are too large for small greenhouse or indoor grow room applications. Some small ones are avai fable or a Coleman lantern, bunsen burner or small gas stove can be used. All of these CO2 generators produce heat as a by-product of CO2 generation, which is rarely needed in a controlled environment grow room but may prove beneficial in winter growing and cool area greenhouses.
The rate of CO2 production is controlled by the rate at which fuel is being burned. In a gas burning CO2 generator using propane, butane or natural gas, one pound of fuel produces approximately 3 pounds of carbon dioxide gas and about 1.5 pounds of water vapor. Approximately 22,000 BTUs of heat is also added. These figures can vary if other fuels are used.
To relate this to our standard example in an 8' X 8' X 8' growing area, if you used ethyl or methyl alcohol in a gas lamp or burner at the rate of 1.3 oz. per day, we would enhance the atmospheric concentration of CO2 to 1300 PPM if the room was completely sealed.
An enrichment standard of 1300 PPM was chosen as it is assumed that 1500 PPM is ideal, and that the plants will deplete the available CO2 supply by 100 PPM per hour. Remember, the normal atmosphere contains 300 PPM of CO2. A 100% air exchange (leakage) every two hours is assumed to be the average air exchange rate in most grow rooms and tight greenhouses. If many cracks and leaks are present, this exchange rate will increase significantly, but added CO2 (above 300 PPM) will also be lost. If a vent fan is in use, disregard CO enrichment, as it will be blown out as fast as it is generated.
A circulation fan is beneficial, as it moves the air about in the greenhouse or grow room. If the air is still, it can cause a "depletion layer effect". This effect causes the CO2 right next to the plant leaf to be quickly depleted. If fresh air carrying additional CO is not brought to this surface, photosynthesis and growth will diminish and eventually cease.
There are a number of factors involved in keeping the CO2 content at the desired concentration level. 1. If the greenhouse or grow room is not tightly sealed up, add up to 50% to the CO2 generator production volume. 2. If temperature is increased fiom 70 F to 90 F, add 20% to the volume generated, and vice-versa. 3. If the grow area contains large or tightly spaced plants, add 20% to 30% to the CO2 volume generated.
If more light is used, more CO2 can be utilized and should be produced proportionately up to the practical limit of 5,000 footcandles per square yard and 1500 PPM CO2 atm. content. When more CO is generated, more water and plant nutrients should be used, again to a practical limit of 2X normal. lf your plants are going to grow faster because of CO2 enrichment, they will need more nutrient and water.
The last factor to consider in maintaining a set CO2 level is the size of your growing area. This is simply done for gas burning and following methods by setting up a mathematical ratio. In our "standard" room (8' X 8' X 8'), we have 512 cubic feet. If your growing area measures 10' X 10' X 20', you have 2,000 cubic feet of volume to contend with. If you want to use the ethyl alcohol/gas-lamp enrichment method, set up the ratio using l.3 oz. by weight of alcohol per day gives:
1.3 oz./day = 512 cu. ft.
------------------ -------------------
X oz./day = 2,000 cu. ft.
Then cross multiply: 512 X = 1.3 X 2,000. Dividing both sides by 512 gives you X = (1.3 X 2000)/512, solve for X. X = 5 oz.
You need 5 oz. of ethyl alcohol per day in a 10' X 10' X 20' grow area to generate the same amount (1300 PPM) of CO2 as in a 512 cu. ft. room.
To generate 1500 PPM above the available CO2 (200 PPM) in the same size area, set up the ratio:
1300 PPM = 5 ounces"
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