DIY $5 Co2 Generator

[GardenTHIS]

Just about everyone wants to eventualy have a great Co2 system in their grow, but its just too expensive for the average grower to afford. So here is a very inexpensive yet effective Co2 generator that I use in my grows.

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You will need:

1 Soda Pop 2L Bottle
2 Cups of Sugar
1 tbs of Baking Soda
1 packet of Yeast
2 cups of warm water
2 cups of cold water

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1. Clean out your 2L bottle with some water, and in a medium bowl, stir in 2 cups of sugar into 2 cups of warm water.

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2. Poor the mixture into the bottle.

3. Mix 1tbs of Baking Soda with 2 cups of cold water.

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4. Pour this mixture into the bottle.

5. Shake the bottle well.

6. Add the packet of yeast to the mixture, but allow the yeast to sit at the top and do not shake the bottle.

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7. Place the bottle in your grow room!

The life of the mixture lasts about 12-14 days. Every 4 days or so you may want to begin stiring the bottle gently to activate more yeast. You should notice a difference in plant growth in about 3 days. Take pictures to capture the explosion.

If you use this Co2 generator, please let me know how it works out for you!

-GT

[Cranky]

Pretty cool info there GT2thumbs

Any info on how much Co2 is given off?

cranky

[GardenTHIS]

I looked about, and I couldn't find any info on the output... I'd say let your nose be your guide. You can also use the cap with pin-holes to control when and how much is released, but avoid complete closure or it might explode :D

Once the mix is made, the next day you can catch that distinct odor and then one day you may notice its not as strong as it could be and might be time for a remix or to adjust the holes in your cap(s).

Hope this works out for you!

GT

[Shadows]

When you mix a new batch, add 1 cup of the old batch. The active bacteria will mean less time before your mix is up to full output. You can also add back a 1/2 cup of sugar 4-5 days through the process and extend its life a few days.

[GanjaGuru]

Unfortunatly, that method will cost the grower more in yeast & sugar than it will yield in increased bud.
To use CO2, it must be in a sealed environment and be administered above the plant (since CO2 is heavier than air).
You also should have a way to exhaust it during lights out when it's not needed.

There is a misconception of what CO2 does.
It doesn't mean bigger buds. In fact it shouldn't be used after the first 3 weeks of 12/12.
What CO2 does:
Let's say you veg your plants to 15" tall before flowering them.
Adding CO2 will get them from seedling or clone to 15" faster than without it.
How much faster?
If you have excellent flo-thru ventilation, 2 or 3 days.
That's it folks.
For the commercial grower, CO2 augmentation makes sense. You're growing successive crops and after awhile those extra days add up.
But for the average home grower, excellent flo-thru ventilation is more cost effective than CO2 augmentation.

[dredank]

doesnt co2 increase trichome production?

[GardenTHIS]

Unfortunately, that method will cost the grower more in yeast & sugar than it will yield in increased bud.
To use CO2, it must be in a sealed environment and be administered above the plant (since CO2 is heavier than air).
You also should have a way to exhaust it during lights out when it's not needed.

There is a misconception of what CO2 does.
It doesn't mean bigger buds. In fact it shouldn't be used after the first 3 weeks of 12/12.
What CO2 does:
Let's say you veg your plants to 15" tall before flowering them.
Adding CO2 will get them from seedling or clone to 15" faster than without it.
How much faster?
If you have excellent flo-thru ventilation, 2 or 3 days.
That's it folks.
For the commercial grower, CO2 augmentation makes sense. You're growing successive crops and after awhile those extra days add up.
But for the average home grower, excellent flo-thru ventilation is more cost effective than CO2 augmentation.

I will have to slightly disagree with you "GanjaGuru" and I want to make sure that folks reading this arent lead astray.

1. CO2 does not HAVE to be administered above the plants. Air circulation IS required inside your grow chamber to insure that the co2 doesn't settle.

2. The fact that you only use it up to 3 weeks into flowering is not absolute, nor would I suggest to anyone that they follow that same cycle. As an experience grower knows, all strains are different. 3 weeks indica to 3 weeks sativa is like Dog-to-human years, sativa takes a little longer in the same 3 weeks.

3. Plants use c02 in ALL stages of production. Any additional co2 ppm in the environment would obviously be beneficial, regardless of the amount.

-
Below is details information regarding Co2 for you to make your own informed decision.

-GT

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The entire artical can be found HERE (http://www.hempcultivation.com/420/showthread.php?p=544318#post544318)

CO2 Enrichment Guide
In an attempt to educate myself (and provide a resource for the HC.com community), I have been researching and assembling what I hope is a comprehensive guide to CO2 enrichment. I felt like there was a lot of speculation out there, but no real definitive or empirical guide. So here it is!

CO2 ENRICHMENT GUIDE

Carbon dioxide (CO2) is used by plants in photosynthesis, or the conversion of water, atmospheric carbon dioxide and light in the plant's chloroplasts into food energy (simple carbohydrates), with oxygen as a byproduct. Resins and saps in the plants stems and branches then transmit this food around the plant to promote growth, reproduction and prevention of disease.

Photosynthesis stops at night, thus plants do not use CO2 during the night, or lights-out stage. Although enrichment of the atmosphere during the night cycle will not harm the plants, efficient CO2 systems are regulated so that when the lights go out, CO2 emissions stop.

Ambient air at sea level contains approximately 350-500 ppm of carbon dioxide. Higher altitudes and rural locations typically have a lower presence of CO2, while lowlands and urban areas have a higher presence. CO2 can be measured, in parts per million (ppm) of air, using an inexpensive device available in hydroponics supply catalogs and garden shops (approx US$20).

Carbon dioxide enrichment involves increasing the concentrations of CO2 to 4-5 times the normal atmospheric levels, to between 1200-1500 ppm in an enclosed space. Enrichment has been shown to promote faster growth, higher yields, and stronger, healthier plants. Levels higher than 2000 ppm have been shown to retard plant growth. Low levels of CO2 (below 200) have been show to halt vigorous growth, even when all other conditions are ideal. Because of this, any enclosed space requires replenishment of the internal CO2 as it is used by plants, either from ventilation or from CO2 supplementation.

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Temperature, humidity, and CO2 concentrations form a triangular relationship in a greenhouse or indoor grow. If all 3 factors are not in equilibrium, there is a risk to the plant in terms of stunted growth, toxicity, or death/disease.

Standard growing conditions typically include concentrations of CO2 at 300-500 ppm, temperatures between 65-80°F, and relatively low humidity (20-40% rH). Studies have shown optimal growth and yields at 90-95°F, 1,500 ppm CO2, 45-50% relative humidity, 7,500-10,000 lumens/square foot of light, and vigorous air movement both above and below the canopy. CO2 enrichment under 80°F, under 7500 lumens/sf, or above 50% humidity is not recommended because plants will not be conducting photosynthesis quickly enough to benefit from the enrichment.

Internal air movement in the grow room is critical to CO2 enrichment. Carbon dioxide is a slightly heavier molecule than other molecules floating around in the gaseous mixture we call air. Thus, CO2 enrichment without air movement will result in the gas settling out of the atmosphere before it has a chance to reach the plants. High temps and humidity without air movement can also encourage mold and bacteria growth.

To calculate the amount of Carbon Dioxide needed to enrich a room to 1500 ppm, first calculate the volume of the growing space. For instance, an 8x8 foot room with an 8 foot ceiling would contain 512 cubic feet of space. Determine the CO2 needed to enrich to 1500 ppm by multiplying the volume of space by .0015.

512 x .0015 = 0.768

Thus, 0.768 cubic feet (or rounded up to 0.8 cu ft ) of carbon dioxide will be needed to enrich this room at 1500 ppm. 1 lb of CO2 is equal to about 8.5 cubic feet at normal temperature and atmospheric pressure.

The rate at which carbon dioxide needs to be replaced is purely a function of how much ventilation the space receives and how many plants are consuming CO2 in the grow space. Only testing monitoring will ensure CO2 levels remain somewhat constant. Grow rooms that rely heavily on external ventilation to control temperatures or smell should not consider CO2 enrichment, because any gas introduced to the space will be blown out as quickly as it's created. A sealed room that relies on no external ventilation is ideal for CO2 enrichment. Since the ideal temperature for CO2 enrichment is much higher than normal, growers who employ this technique will need much less ventilation (if any).

For those who still want or need external ventilation, CO2 enrichment will only succeed if exhaust and enrichment are timed and set on opposing cycles. For instance, in a flowering room an exhaust fan timed to operate during the night would not conflict with CO2 enrichment during the day, when plants can use the additional gas. In vegetative growth rooms, the fans and enrichment would need alternating cycles to make enrichment worthwhile. For those growers using unregulated sysems, CO2 output should be adjusted for both speed and volume to make up for the exhaust.

There is some anecdotal evidence that charging nutrient solutions with seltzer cartridges will encourage plant growth in some hydroponics systems. The CO2 is released into the atmosphere as a byproduct of nutrient movement in the hydro system. This method has not been scientifically proven, nor would not be effective in aeroponic systems where nutrients are largely contained in separate tubs from the leaves and branches of the plant. Spray ring and ebb/flow systems may have the best potential for success with this method.

METHODS OF CO2 PRODUCTION

Tanked CO2

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Tanked CO2 is by far the most reliable and controllable method of CO2 enrichment. Bottled CO2, usually available from welding supply and bottled gas vendors, is metered out via regulators and solenoids. It is possible to very finely regulate the amount of CO2 in the atmosphere using technologically advanced digital regulators. In many areas, licenses or permits are required to obtain bottled compressed gasses due to safety regulations.

Advantages
-Very fine control of CO2 using regulators
-Easy to automate, hassle free once set up

Disadvantages
-High initial cost of equipment
-Logistics of delivering and returning heavy bottles to a secure grow area
-The tank becomes a deadly projectile in a catastrophic failure, or can cause a significant and dangerous explosion in a fire.
-Rapid, unexpected release of CO2 can cause over-enrichment and asphyxiation of room occupants.
-Permit/license requirements may make bottled gas difficult to obtain

Combustion

Fuels such as ethyl alcohol, natural gas, or propane produce CO2 as a byproduct of combustion. Burning of one pound of clean burning heating fuel will produce 3 pounds of carbon dioxide gas, 1.5 pounds of water vapor, and approximately 22,000 BTU of heat.

Devices which help attract and kill mosquitoes in outdoor yards use propane fuel tanks to create carbon dioxide. The insects are attracted to the CO2, which in nature is an indication of a food source. These devices burn propane in a tightly regulated, low temperature combustion chamber. Although these would probably be the lowest temperature application of this method, any indoor storage of propane, natural gas or other bottled, explosive gasses is highly discouraged.

Ethyl alcohol (available as denatured alcohol in hardware stores) is a readily available material and can be safely burned indoors in small stoves or lamps. Ethyl alcohol is also the primary reactive component of Sterno and similar gel fuels.

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In our sample room (8x8x8), we would need to create about 1 lb (8.5 cu ft) of CO2 over a 24 hour period. To find the volume of ethyl alcohol, we first need to find out how much ethyl alcohol weighs. Water has a specific gravity of 1.0, but ethyl alcohol's specific gravity is .79. Since one gallon of water weighs 8.33 lbs:

8.33 x 0.79 = 6.58 lbs

Thus, 1 gallon of ethyl alcohol weighs 6.58 lbs. Since 1 lb of fuel creates 3 lbs of CO2, only .333 lb of fuel would be needed to create 1 lb of C02.

By ratio and proportion:

6.58 lbs * X gals = .333 lb * 1 gal

X = .333/6.58 = .051 gal

Since 1 gal = 128 fluid ounces:

.051 gal * 128 ounces = 6.48 ounces

Thus, we would need to burn 6.48 ounces of ethyl alcohol per day (a little more than 3/4 cup) to enrich a completely sealed room. The amount of CO2 needed (and thus fuel) would increase with any supplemental air changes. There is some evidence that active combustion can help control odors in enclosed spaces.

Coleman stoves, bunsen burners, portable propane space heaters, and other similar devices are all potential sources of carbon dioxide as long as they are used safely.

Advantages
-Inexpensive to set up, depending on method chosen.
-Heat can be beneficial if temps are low, such as in a cold basement grow room.
-Output can be regulated by size of flame
-Can provide slight odor control.

Disadvantages
-Open flames in enclosed spaces create a fire hazard
-Additional heat produced by combustion adds to heat already produced by HID lighting.
-Can be difficult to burn enough fuel to achieve optimal enrichment without adverse side effects, such as carbon monoxide.
-Indoor storage of bottled fuels is potentially dangerous.

Fermentation

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It is widely known that CO2 is a byproduct of fermentation. CO2 is the gas found in bubbly beverages, such as champagne and beer. The same process that "carbonates" these beverages can be harnessed to create CO2 for a grow area. A pound of sugar will ferment into approx. 1/2 lb of ethyl alcohol and 1/2 lb of CO2. We've determined that we need 0.8 cu ft of CO2 for our 512 cu ft grow room (see above.) Then calculate the size container needed by dividing the size of the grow room by 32.

512 / 32 = 16 gallons. (A tall kitchen garbage can would make a good 16 gal. bin)

Assuming that the bin will produce half alcohol and half CO2, the bin will consume .16 lbs of sugar every four hours, which is roughly 1 lb per day. This means that about 45 lbs of sugar will be used over 6 weeks (assuming that not all sugar is completely converted to alcohol).

To get the process started, mix a pinch of yeast, 12 ounces of warm water and a half-cup of sugar and keep warm and covered until bubbles form in a day or so. Use this mixture to inoculate the main bin.

To create a yeast bin mix, dissolve 3 lbs of sugar per gallon of boiling water. Cool the mix to 80°F before adding the yeast. Locate a container with a tightly fitting lid. The lid should be equipped with a hose to direct CO2 gas towards a fan for distribution into the space. Increased air pressure in the bin will force the gas out of the hose.

Both canister and lid should be thoroughly cleaned with hot soapy water and rinsed well before use. Start off the bin a little more than half full (10 gallons of water and 30 lbs of sugar). Every week, add another gallon of water and 3 lbs of sugar. The yeast bin must remain at 80-85°F for the reaction to continue.

To monitor activity and prevent contaminants from entering the bin, create a fermentation lock by placing the end of the hose into a glass of distilled water. The bubbling water will be an indicator that there is still a reaction in the bin and prevent bacteria from entering the bin through the hose.

Our bin will need to be completely replenished every 6 weeks, or when the bubbling slows. A simple taste test will tell if the bin needs replenishing. If the taste is sweet, there is still sugar in the water and the reaction should continue. If the taste is dry like wine, the bin is mostly alcohol and should be replenished. Some growers preserve a cup of liquid from the old bin and use to inoculate the new bin, however if an infestation is starting to occur, this can contaminate an otherwise fresh bin with bacteria. It's just as easy to inoculate with new yeast as above, and extra yeast stores easily in the refrigerator for months. Corn sugar (available at wine making shops) is a less expensive fermentation medium than regular cane sugar. Other fermentation mediums can be used depending on materials cheaply and readily available to the grower. Corn syrup, maple sap, even old fruit juice can be fermented, although with increased odors and more waste cleanup when the bin is refreshed.

Advantages
-Easy to create with simple materials
-No safety dangers
-Inexpensive materials when purchased in bulk (sugar)
-Ethyl alcohol byproduct can be siphoned off and burned in alcohol lamps for supplemental CO2 enrichment

Disadvantages
-Difficult to regulate
-Fermentation can produce odors
-Large yeast bins are heavy and hard to move.


Dry Ice

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Dry ice is nothing but carbon dioxide in its solid form. Dry ice is commercially available nearly everywhere for industrial, medical, and theatrical (fog machine) applications. One pound of dry ice is equal to 8.5 cubic feet of gaseous CO2. Create a CO2 chamber by poking holes in the sides and top of an insulated box, foam cooler, or similar container that can insulate the material from human skin and plants. The box also helps insulate the solid ice so that it vaporizes more slowly. Ideally it should take an entire day for the chunk of ice to vaporize, although smaller chunks may need to be added at intervals through the day to maintain 1500 ppm.

Some growers place their containers of dry ice directly over grow lights. The falling CO2 bathes the plants beneath them and also helps control temperatures from hot lights.

For our 512 CF grow room, about 1 lb of dry ice per day would be needed to keep CO2 at 1500 ppm. At $.60/lb, dry ice would be a very cost effective solution. Storage of dry ice in a home freezer will slow it's vaporization, but dry ice is hard to store ahead because doesn't have a long shelf life. Not many homes have freezers capable of maintaining -109°F.

Advantages
-Inexpensive, widely available material
-Easy to construct and maintain
-No risk of catastrophic failure
-Dry ice has slight cooling effect

Disadvantages
-Impossible to regulate evaporation
-Must be used immediately - has no shelf life
-Can harm skin if handled without gloves.

Soda/Acid

Baking soda and acetic acid solution, such as white vinegar (5% acetic acid), will bubble and foam when mixed. The bubbles produced are carbon dioxide. Unfortunately, large quantities of materials are required to produce carbon dioxide adequate for enrichment, making this solution viable only for very small closet grows.

To produce 1 lb of CO2 every day for our 512 cu ft test grow room, we would need to mix about 2 lbs (1.91 to be exact) of baking soda with 3.25 gallons of 5% acetic acid vinegar. As you can see, the costs for baking soda and vinegar would add up quickly. For a small closet or cabinet operation, it may be a workable solution though. A small drip setup can be placed on a top shelf of the closet, with the CO2 cascading down onto the plants (so long as it's not sucked out by vent fans).

Mixture of appropriate amounts of vinegar and baking soda will quickly fill a small room to acceptable enrichment levels. From there, a simple drip irrigation system can be created to steadily regulate CO2 levels, using a reservoir of white vinegar suspended over a tub of baking soda. A hose with a small pinhole is a good way to create a steady regulated drip. Calibrate the drip with a pushpin or small nail until the hole allows the desired amount of vinegar to drip through in a 24 hour period. An added bonus to this method comes from baking soda's odor neutralizing effect when left open to the air.

For slightly larger operations, 1 lb of carbon dioxide can be created from 2 lbs of baking soda and 1/2 gal of 33% muriatic acid, which is an chemical additive used in swimming pools. Although this is more cost effective, it is still more expensive than some of the other methods mentioned. Muriatic acid (a.k.a hydrochloric acid) is also highly caustic which can cause serious chemical burns if mishandled.

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There are commercially available machines which produce CO2 this way, by mixing baking soda with muriatic acid using mechanized agitators. These units do not have regulators, solenoids, or pressurized compartments to store gas during the off cycle. Any jug made from plastic that can withstand a caustic material such as muriatic acid would be equally effective.

Advantages
-Easy to set up with simple, readily available materials.
-No risk of catastrophic failure
-Slight odor control benefit from baking soda.

Disadvantages
-Difficult to regulate during off cycle
-Can take a long time to build up a proper CO2 enrichment
-Materials can be expensive over time unless purchased in bulk.
-Some chemicals can be caustic.

Breathing

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The natural breathing of air by people is also a way to contribute carbon dioxide to an enclosed space. Some quick calculations show that one person breathing can actually provide a significant amount of CO2. Although the total lung capacity is approximately 7 liters, the natural tidal volume (each normal breath at resting) is about .5 liter (5000 cubic centimeters) per breath.

To convert cc to cubic feet, multiply by 3.531 x 10^-5

0.00003531 x 5000 = 0.17655 cubic feet of air

Since each breath made at a rest is 5% carbon dioxide:

0.17655 cu ft air x .05 = .0088275 cu ft of carbon dioxide

And since a person breathes approximately 14 times per minute at rest:

.008275 x 14 = 0.123 cubic feet of CO2 per minute.

Our room requires 0.8 cubic feet of CO2 to reach 1500 ppm, which it will attain after only 6.5 minutes of normal breathing. However, that enrichment is quickly absorbed by the plants. Assuming that we require 1 lb (8.5 cu ft) of CO2 per day for our 512 cu ft grow room:

8.5 cu ft / 0.123 cu ft per minute = 69.1 minutes

Thus to enrich our room to 1500 ppm day, one average sized person would need to spend approximately 70 minutes per day in the grow room assuming the room was completely sealed. Spending this much time at once could elevate carbon dioxide to unhealthful levels, but several stops in the grow room spaced out during the day (perhaps 35 minutes in the morning and 35 minutes in the evening) would keep CO2 concentrations elevated to optimal levels.

Of all the methods mentioned, breathing for CO2 enrichment is free and requires no special tools, additives, equipment, or skills. Breathing produces no unhealthful byproducts or hazards. Most gardeners spend a good amount of time in a grow area looking over the plants for bugs/disease, pruning them, mixing nutrients, admiring, etc. Entry to the room should minimize CO2 loss, through an airlock for example. As long as the space is well sealed and the air is vigorously circulated, normal breathing could produce all the C02 needed to enrich a small to medium sized room if it's visited and tended daily. One of the other supplemental methods can make up for times the gardener is away from the room for extended periods oftime. Working in any enclosed space requires caution and alertness to avoid asphyxiation.

Advantages
-Requires no tools, equipment, or setup
-Free
-Byproduct of being in the garden working

Disadvantages
-Multiple stops into the garden daily are required
-Slight risk of asphyxiation from being in an enclosed space too long
-Entry to room without an airlock will eliminate any gains.

Cost & Security Benefits of CO2 Enrichment

Plants in a CO2 rich environment can withstand and need much higher temperatures to derive any benefit. Inversely, CO2 enrichment can help mitigate ventilation and air conditioning challenges in grow rooms, common challenges faced by growers looking to minimize costs and maximize security.

Ventilation to the outdoors is a weak link in any secure grow operation. Exhaust to the outdoors can be detected by close neighbors, especially for growers in townhomes and apartment complexes. In many areas, a tip from a neighbor and detectable smell to the local constable or sheriff could constitute "probable cause" to get a search warrant. CO2 enrichment eliminates the need for excessive exhaust and thus the need for this breach in your security.

The primary operating cost of a residential grow operation is electricity. Reliance on high intensity discharge lights, fans, humidifiers, and pumps for hydroponic systems can nearly double a residential electric bill. Cooling a hot grow area to 75-80°F for normal growing adds another important but potentially expensive challenge. In many older homes, this could require additional electrical circuits, since each standard (15 amp) residential circuit should only power devices totaling about 1500 watts. CO2 enrichment eliminates the need for additional cooling above what's needed to maintain 95°F.

Notes & Warnings

CO2 is widely considered to be a "greenhouse gas", which is thought to be responsible for trapping the sun's radiation in the atmosphere and causing global warming. Commercially available CO2 is the by-product of industrial applications which reclaim gas that would have escaped into the atmosphere anyway. CO2 produced from combustion, fermentation or other means further increases the amount of CO2 in the atmosphere, albeit minutely. Enrichment with reclaimed CO2 is a more environmentally responsible method, however it is also the most expensive and logistically difficult.

Although CO2 is not a deadly gas, it's presence in an enclosed space can deplete the atmosphere of oxygen needed for human occupation, causing asphyxiation. Signs of asphyxiation include weakness, lethargy, dizziness and loss of consciousness. If a grower notices any of these signs for any reason, immediately leave the room and go to a safe space. If these signs then subside, the CO2 in the grow room is too highly concentrated and should be vented immediately.

Many of the methods described in this guide can be harmful or fatal if used improperly. The grower should use extreme caution when using any volatile compound, flame, or hazardous material. Consider emergency situations when designing your system. For instance, bottled gasses will explode or become deadly missiles when punctured or heated by fire. Fuel vapors in the atmosphere can explode suddenly from electrical arcs, open flames, even static electricity. Asphyxiation resulting in unconsciousness and death can occur quickly when a room is over-enriched. If you suspect any form of danger, get to safety first. No plant, CO2 system, or even a whole house is worth a human life.

[GanjaGuru]

doesnt co2 increase trichome production?

Nope.

[GanjaGuru]

Years ago, in an effort to maximize yield I spent nearly $1,000 for 2 tanks, regulator, emitter, atmospheric ppm meter (those meters cost $500.00), built an airtight growspace (a MUST) and bought extra timers and fans.
At first I was amazed at how much faster the CO2-enriched growspace grew my plants vs. my old space with CRAPPY ventilation (an open door).
Then I spent $30.00 to install flo-thru ventilation in my original growspace.
The CO2-enriched growspace got me buds approx. 4 or 5 days quicker than the space with excellent ventilation.
Not more buds, not bigger buds, not more potent buds.
Just a bit quicker.
And then there was the hassle of lugging those damn tanks to a welding shop every 2 weeks. Refills cost $18.00/tank.
It's also advisable to have a "cover story" if someone happens to talk to you about what you're using the tanks of CO2 for.
That's why I say excellent ventilation is more cost-effective than CO2 enrichment for the average non-commercial grower.

And I've also done cost analysis between using yeast & sugar-generated poorly administered CO2 enrichment in real-life instances and in 2 of the 3 instances the yeast & sugar cost more than the slight increase in yield.

P.S. I sold the tanks and ppm meter and the rest of the equip. sits in boxes in a corner of my garage.

There's no doubt that properly administered CO2 at correct levels is an advantage, especially vs. poor ventilation.
But is it worth the cost and hassle?

[Cranky]

basicly,the more co2 the plant gets then the more photosynthesis is able to go on which means more energy which means more growth prodution which mean big fuck off plants:D 2thumbs

will post alittle info on how co2 and plants work in abit2thumbs ;)

cranky

[billo]

the thing that throws me off co2 is the fact that if your plants get sick with the co2 they get sicker quicker
would you get away with out ducting your exhaust??

take care
b

[hydrohustle]

ok I've been wondering for a while now about Co2....

I have two 6 inch vortex fans sucking all the air from the grow room to the outside. The plants get all their fresh air from the living room into the grow room and then out of the grow room's 2 windows. my question is, with all that air pasing through the room will Co2 realy maintain any stand point in the room at all or won't it all just get blown out like the rest of the air..
..try to understand that a whole lot of air is going though this room. An average rotating house fan and two 6 inch vortex fans!....How the #$^& can Co2 possible remain inside the room amongst all that turbulance !??!?!
:D

[Jasper]

I thought that CO2 was administered without fans. But what do I know, I am here to learn. I came to this thread because I did a search on CO2, tons of good info.

Each and every grow I try something new to just make it better. I think I am ready to step this up a bit and give CO2 a shot.

Will try a DIY version before investing. I do admit that I get up close and personal whenever I am near my plants, talk and chat and blow lots of CO all over them. They do like it.

[Mountain]

I gotta in general agree with GanjaGuru. I've recently done some research into uprgading to CO2 and decided it wasn't worth it. Seems like the best I could expect, with a dialed in setup, was about a 15-20% increase in yield. I do think that most setups are severly inadequate in the airflow deartment. Most forget to take into consideration duct line resistance (distance) and kinks/bends which drastically reduce efficiency. Peeps calculate based on their space and equipment specifications and don't take these other dynamics I've mentioned into consideration. Yes CO2 helps but what's the cost to benefit ratio? I truly think that's dependent on how well the current space is engineered. I'm dealing with a situation where I was so tempted to invest in CO2 but soon realized I need better air mixing. There's an awesome sweet spot in the room with two symetrically opposed weak spots. So I added a light, added an inline fan, moved my oscillating fans. I had an air exchange every 60 seconds but this was not enough. I now mix, tumble and recirculate the air around in the room. I throw it back into the space before it exits. The more homogenous the better. One thing I now also try and avoid is excessive turbulence on the plants themselves. This kills yield. After what I've recently seen I'd rather let stakes and trellis netting support the plants instead of having them build stronger stems and branches with wind blowing on them. Why have them put energy into something that's not necessary? One thing I seem to see is with all the equipment, CO2 and associated stuff, there's better regulation of the environment, temp and humidity high/lows, and that in and of itself heps out.

I'm not trying to devalue the thought or methods of introducing CO2 as it does work to some extent but do believe that peeps need to look at more simple solutions to increase yields and general plant health :watch:.

[Mr. Bud]

Ok, here is a good way to kill two birds with one stone.. Anyone ever made wine? Go to you local wine making supplier and pick up a fermentor and a couple of one gallon jug carboy's with airlocks for each one.. Get what ever product you want to make wine out of; concetrated grape juice, apples, berries or what ever you want to use.. The wine store will be albe to tell you what you need for your wine making as far as how much sugar and yeast to use... Stir that shit up and put it in your grow room. The airlock on top will keep an even amount of co2 entering the room and from start to finish will get you about 3-4 weeks of co2.. I could be full of crap here but it seams like the wine is good to drink and the pot is good to smoke so what the hell...:sodrunk:

[drumin]

Would introducing CO2 into a room with poor ventilation help much? My grow room has no windows and one door. I vent air out of the room through an actual vent with fan I installed. The plants get the same air I breath...

[Mr. Bud]

From what I understand; and I am no pro by any means, the importance is a steady leval of CO2 is what you are after.. The plants take several days to start using the CO2. They have to get used to it being there before they will be able to process it. All it really does is speed up the grow process and you will yield a some what larger or more compact bud..

[SpanglyBoovus]

Ok, here is a good way to kill two birds with one stone.. Anyone ever made wine? Go to you local wine making supplier and pick up a fermentor and a couple of one gallon jug carboy's with airlocks for each one.. Get what ever product you want to make wine out of; concetrated grape juice, apples, berries or what ever you want to use.. The wine store will be albe to tell you what you need for your wine making as far as how much sugar and yeast to use... Stir that shit up and put it in your grow room. The airlock on top will keep an even amount of co2 entering the room and from start to finish will get you about 3-4 weeks of co2.. I could be full of crap here but it seams like the wine is good to drink and the pot is good to smoke so what the hell...:sodrunk:

This sounds friggin awesome since there will soon be wine making going on around here.. :D

[Mountain]

I really don't see that introducing CO2 into an open system will be of much use. I guess the poorer the ventilation the greater the benefit though. When touring breweries...hicup...it always caught my attention the amount of CO2 those places generate that just gets wasted. The room I currently work in has an air exchange every 60 seconds or less. The air inside the room is pretty much what you get outside the house but warmer. Any injected CO2 would just go right out the exhaust for me.

Hey Spangly...gonna dust some girls tonight...thanx mucho :D.

[Cakes]

When I brew I put a plastic bag on top of my 5 gallon buckets so the gas has somewhere to go and yet the contaminents do not get in. The bag expands about 2 cubic feet over a period of five days and then the reaction is over. The reaction ends because the alcohol level in the bucket has reached about 12%. Special yeast can be bought that will keep working until the alcohol level reaches about 14%.

I didn't see the above equations taking this factor into account.

And I have seen other equations (in other threads) show that home scale brewing is not capable of releasing enough co2 to be helpful to plants. So, I am interested in pictures (or % of increase reports) too...
Take pictures to capture the explosion.

I did, once, try suspending bottles of fermenting material above my grow but since the reaction was so short lived, I gave it up. I am really on a tight budget and use my sugar for myself :)

so, even though I have no real experience I will share that I, too, have heard reports of lowered bud quality if co2 is used during their active formation rather than just during veg.

and I have also heard that growers can cut a 1/3 off their veg time, not just a few days. Perhaps implementation is a key factor.

I have also read a few texts which say that plants switch respiration at night. They not only cease to intake co2, they actually begin to take in oxygen.

My next plan is to import some of the exhaust from my propane water heater to my grow.

[Cranky]

My next plan is to import some of the exhaust from my propane water heater to my grow.

there was a lad that used one of those for the same purpose....maybe he will chime in and let us know how that went???

as much as i would love to try co2...i cant....just dont fancy putting the wife and kids in a permanent sleep....wellllllll not yet anyways:p

and yep...plants wont use co2 at night/lights off;)

cranky

[Lungus]

so, even though I have no real experience I will share that I, too, have heard reports of lowered bud quality if co2 is used during their active formation rather than just during veg
I have been using bottled CO2 for 6 years and the only way bud quality might be lowered is in the smell and taste. CO2, at least the bottled stuff tends to deaden the smell of the bud a little, which depending on your situation might be a good thing, but I have found no evidence to reduced quality. I use CO2 for veg and flowering except for the last two weeks of flower where the plants aren't really growing any more, the bracts are just puffing up. As to killing your family with CO2, not much chance of that, especially if you have a smoke detector with a CO2 sniffer. When using CO2 it should be metered to keep the room at 1000-2000 ppm of CO2 and it doesn't become a serious risk to human health until it hits the 15,000 ppm level, so unless you crank the valve open on the tank inside the house, it shouldn't be a problem. CO2 will provide benefits when everything else is dialed in. If you have other problems with your grow the introduction of CO2 to your grow isn't going to fix them, it's got to be running good beforehand for the CO2 to make a real difference. Then once you do start using CO2, your going to have to change the way you ventilate because if you are constantly exchanging air all you'll do is suck out all of your valuble gas or you'll have to add so much that the cost will be more than the benefit. To overcome this problem your ventilation can be put on a timer or a thermostat, so that it allows the room to be saturated with CO2 for a time, then exchanging the air to get rid of the heat and transpirated moisture. My method is a little more complex but it is the same basic principle. Here's a link to a thread that descibes my system, but be warned it took years to get all this stuff together but it might give you some ideas that you could incorporate into your design.
unleashthegreen.com/community/view_topic.php?id=8878&forum_id=12&highlight=grow+box"]http://unleashthegreen.com/community/view_topic.php?id=8878&forum_id=12&highlight=grow+box

[ice#1]

let you know how it works just mixed up a batch last night turned the exhust fan off this morning this is just in my clone room

[Cakes]

That's cool, Dude. Hands' on tests are the way to go.

And I gotta say that I agree that the chances might seem slim of an accident involving CO2 but it is quite possible if one uses the figures given by Lungus.

love that peek-a-boo window

CO2 displaces the lower air in a room if there is no fan. If one has a room where the CO2 is 2000 ppm and it is allowed to settle to the bottom 1/3 of the room (typical heighth of a bed), then one would have a concentration of 6000 ppm. This is just two and a half emitter cycles away from the dangerous level of 15,000. So an emitter only needs to emit it's CO2 for a couple of cycles before the level reaches serious proportions. An exhaust fan can fail or a grow room may be in a closet or other proximal location..

or instead of the CO2 coming at normally scheduled times, it may begin to be emitted at a rapid rate through accident; like the failure of a timer..

And in my case, where I raised the idea of using a propane hot water heater, there is the issue of carbon monoxide; which is different from carbon dioxide. carbon monoxide does not wait for O2 deprivation to kill you. It is quite toxic on it's own. And this is why you do not hear of people dying from carbon dioxide poisoning in heater accidents; it is the carbon monoxide which gets them first.

and when one has a family, then are not only equipment failures (I've never used a fan that long but my cheap timers fail approx. every six months) but one has to contend with gravity and earthquakes and kids. And, well, you might know this, but they are very busy people. inquisitive. active. ingenious. exhuberant.

i really do like that peek-a-boo window on the linked grow

[ice#1]

yes with burning things to produce c02 is the ony way to get carbon monoxide if you have a tank of c02 thats all thats in it just c02

[Mr. Bud]

Here's what I made... This is my first grow so I am not sure if it helped or not.. Just wanted to show my set up.. I could really detect the CO2 in the room.. Also, my veg room is 5x7x5 and pretty well sealed.

Check out the photos... Last one is week 5 flowering

[Cakes]

I like the nifty splitter and dispensers.

I read somewhere that the stomata on the undersides of the leaves intake CO2. If the dispensers were aimed up from underneath the canopy, then it would save moving them so often as the plant grew. You could put an air pump on it with a connector between the jug and the splitter. if a Y shaped intake was used then the air would suck any ambient CO2 along as it flowed to the splitter and out to the plants. and so then we'd have CO2 enriched air under pressure aimed at the stomata/plant's pores. A plant's ability to intake those gasses is passive and it is the air movement and whatnot that carries the molecules into and out of the stomata openings.

i'd use it even if I didn't have a jug of hootch attached and I'd put the pump down low where one may expect to find CO2 that has settled out of the atmosphere.

neat tek Mr. Bud.

[Lungus]

or instead of the CO2 coming at normally scheduled times, it may begin to be emitted at a rapid rate through accident; like the failure of a timer..
The timer I used is a microtimer with a phote-eye, and it doesn't come cheap. It was $200 but worth every penny as it's ran problem free for 6+ years. This type of timer is almost essential because with cheaper timers the timers can't be set for smaller release times and can't be set for enough release events to happen during the day.
Oh, and a comment about CO2 being heavier than air. If your room is completely still as Cakes says it may settle, but we all use fans to keep air moving across our plants because if we don't little microclimates can get set up around the leaves and with no air movement they get starved for CO2. It doesn't take a whole lot of air movement to keep the CO2 suspended and I use this analogy to describe it. If winds aloft can keep hail the size of golfballs suspended, CO2 molecules in the face of the breeze from a fan would be blown at will, even the air convection from the heat of the light may be enough to suspend the CO2 molecules.