CO2 Application

iceste

Member
I got a brick of dry ice and put it in a cooler. I open the cooler during the day and I close it when the lights are off. Is this how it's supposed to be as far as absorbed when the lights are on?
 

SkunkDunks

Active Member
I'm not too familiar with the specifics of CO2 in a grow room but I know that CO2 is heavier than oxygen so you would want your source above the plants so the gas can 'fall' onto them, if that makes sense. If you have the brick in a styrofoam container try drilling holes in the bottom of it and placing the whole unit on a shelf or something. Dry ice 'melts' into a gas so you don't have to worry about any mess.
 

spandy

Well-Known Member
For the plants to properly utilize co2 supplimentation, you aren't suppose to have more than a 200ppm fluctuation during lights on.
 

iceste

Member
Well I'm just putting them high enough to fall on the plants but I'm not sure what ya mean by 220 ppm, Spandy?
 

LVTDY

Well-Known Member
The concentration of co2 in the air, is what he means. You ideally would have a sealed room with your co2 source overhead. It would give off co2 at a steady enough rate to maintain your desired concentration of gas without any major fluctuations.

Co2 is only effective in sealed rooms where the exhaust fans are seperate from any light fans or anything.
 

spandy

Well-Known Member
Well I'm just putting them high enough to fall on the plants but I'm not sure what ya mean by 220 ppm, Spandy?

LVTDY already answered, but just to double up lets say you want to have your co2 levels at the prime level of 1500ppm. You want to keep your ppm range as close to 1400-1600 as possible, or 1300-1500, or however you want to slice it. Remember this is only when the lights are on as plants don't utilize co2 when in a dark period.

This is why I have a hard time believing that homemade co2 kits that are unmonitored have any real benefit as a person would have to assume that the co2 levels in the room are all over the board. I don't doubt they help some, but I do doubt that its worth the effort and time. Now any monitored co2 kit, homemade or not, that you can keep your ppm in order is going to kick some major growing butt to say the least, but to achieve the ever elusive "double yield" that some guys can achieve with co2 supplimentation, your ducks gotta be in a nice little row.
 

NoDrama

Well-Known Member
I have used CO2 for years, NEVER have I seen a double in the yield. 10-20% more yes, but not 100%
Dry ice is a pathetic waste of co2 for plants, like has been mentioned you want at least 1,500 parts of CO2 per 1 million parts of air (PPM) and you want this to be regulated so it stays at that level throughout the lights on period. You need a CO2 controller, a Tank (lease or purchase) and some tubing and a regulator. http://www.4hydro.com/growroom/capppm3.asp
http://sodadispenserdepot.com/pics/Reg5125.htm
http://www.beveragefactory.com/draftbeer/tanks/co2/C20.shtml
http://www.omega.com/ppt/pptsc.asp?ref=TYUTH95&nav=

should be doable for a pretty darn decent mini system for under $600
 

spandy

Well-Known Member
I have used CO2 for years, NEVER have I seen a double in the yield.
Me neither, 30% has always been where I landed, but a few years back I watched a side by side comparison of a med grower that was helping me and they were hitting 60-70% increases.

Too many variables, but 20-30% seems to be where most of us land, and it's well worth it!
 

spandy

Well-Known Member
should be doable for a pretty darn decent mini system for under $600
My controller was 450 (sentinel cppm-4)
Regulator- 150
Tanks- used for $50 for each 20 pounder...I basically stole those tanks from that guy AND they are aluminum with plastic handles.


If you are doing a sealed setup, you gotta watch out for which CO2 monitor you purchase. Many of the cheaper ones are designed for non-sealed rooms, so when the lights are on and your temps get high and your extraction fan kicks on, it disables the co2 while the fan is running because it assumes it is exhausting the room and not just a sealed light system. I bought the cppm4 because it works completely independant from my fan controller, so when the lights are on and it's spraying co2 and the fan kicks on, the co2 keeps on a going. I use a day/night controller for my fans with a photocell so I can adjust my day temps and night temps seperately without affecting the co2.

And remember, CO2 is heavier than the air around us, so you need to place the tubing either right through the middle of your crop, or above it. Don't just let it spray out the bottom of the regulator or alot of your co2 is just going to hit the ground and stay there.
 
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