Question on CO2 usage...

lilmafia513

Well-Known Member
Got my hands on a full 20 lb. CO2 tank, gauges, and safety shut off.

Now What? I mean i know what CO2 does for the plants, but not sure how to add it into my room, and how much to use.

Any thoughts would be appreciated.
 

lilmafia513

Well-Known Member
thanks messa, but do you know how long it should be on, and when? lights on or off? And for how long?
Thanks
 

lilmafia513

Well-Known Member
Got my hands on a full 20 lb. CO2 tank, gauges, and safety shut off.
Buy a co2 regulator on ebay. $80-100.
See above post.......got that already.
The question was how long to run it at each time, or how to set it to run automatically. If could afford 80 to 100 dollars, i would have just bought it when i started growing....obviously i'm a DIY kinda guy.

Someone will correct me but it doesn't need to be running when the lights are off. Run 1200 ppm when the lights are on threw the whole grow. That's what I'm gunna try anyways. Unless someone else has some better advice?
Thanks messsa, so you say only run it when lights are on?
My gauges only show P.S.I though. How do i know what the PPM's are.

Would it do any good to just turn it on for a few hours on a low PSI while i am there, or not?

My grow is not at home, so i tend to it when i need to. Cant be there to turn it on, then off when the lights go out.
 

FilthyFletch

Mr I Can Do That For Half
You need the room at 1500 ppm. You also need to have a solenoid regulator for the tank. This attaches to the tank valve and then has a plug to a timer. You set the timer to turn on at certain times for a certain amount of time to get to your 1500 ppm. This is best controlled with a co2 controller or monitor but you can do a manual calculation based on the size of your room but will need the 1 minute cycle timer and the solenoid to open and close the valave. the solenoid can be found on ebay under co2 controller same as an automated controler same search something like co2 controller or co2 monitor. solenoid can be got used for around $50 or $150 new. a digital moinitor controler is luck around $250 use and upwards ofd $3000. Here is a link to a co2 calculator figure the room dimensions add them in and calculate. You use co2 with lights on times only mostly in flower and temps need to be between 80-85 F. Times on will be short usally as in my 4 x8 tents I have it run 4 minutes on every 2 hours roughly. You need a sealed grow room no air outtake except before a fresh fill i do an exchange of air using fans on times and duct dampers to close the vent holes right before a new co2 room fill
http://www.hydroponics.net/learn/co2_calculator.asp
 

lilmafia513

Well-Known Member
You need the room at 1500 ppm. You also need to have a solenoid regulator for the tank. This attaches to the tank valve and then has a plug to a timer. You set the timer to turn on at certain times for a certain amount of time to get to your 1500 ppm. This is best controlled with a co2 controller or monitor but you can do a manual calculation based on the size of your room but will need the 1 minute cycle timer and the solenoid to open and close the valave. the solenoid can be found on ebay under co2 controller same as an automated controler same search something like co2 controller or co2 monitor. solenoid can be got used for around $50 or $150 new. a digital moinitor controler is luck around $250 use and upwards ofd $3000. Here is a link to a co2 calculator figure the room dimensions add them in and calculate. You use co2 with lights on times only mostly in flower and temps need to be between 80-85 F. Times on will be short usally as in my 4 x8 tents I have it run 4 minutes on every 2 hours roughly. You need a sealed grow room no air outtake except before a fresh fill i do an exchange of air using fans on times and duct dampers to close the vent holes right before a new co2 room fill
http://www.hydroponics.net/learn/co2_calculator.asp
Fletch,
Thanks man and I love the new avatar. Tits is way better than your initials etched in pot!!LOL!!! Personal collection, or internet goddess?

Thanks for the link and the tips. I guess i'll look into the gauges on ebay, but cant really afford them at the moment.

Would it be okay for me to just close the vents off, not a problem, and open the valve on a low PSI for about an hour, then go in and switch it off?

If it will do anything at all, i'm willing to try it. Purely experimental of course.:joint:
 

FilthyFletch

Mr I Can Do That For Half
That a picture of the singer Cassie from BadBoy. her puter was hacked and I have her pictures that were yanked. You can try opening the tank manulally use the calculator to get an idea of how long in the room. You want to have the house from the tank above the plants as co2 is heavier then air and falls. You also want a fan on the floor preferably the tilt kind so it sucks the air and co2 from down low and blows it back up and over the plants
 

born2killspam

Well-Known Member
You don't necessarily need 1500ppm at all times.. That would be ideal, but costly.. Most ppl turn the fans off, and dose to 1500ppm for a few minutes every couple hours, and cooltubes with isolated intakes and exhausts make things alot more efficient since you can tone down the grow area exhaust rate and still expell heat.. I know you're in a dungeon though, and can't dedicate extra ducting in/out..
CO2 meters are EXPENSIVE compared to any other meter in this game.. They do sell little disposable test strips or whatever, but they aren't really cheap either.. You just need to figure out how long it takes to raise the desired amount given your space (at the plant height), then use timers from there..
Some rough math:
1lb CO2 = ~10 moles of CO2..
10 moles of any gas will occupy ~8cuft at STP
So diluted to 1500ppm, 1lb of CO2 will create ~5200cuft of ideal plant air.. Actually about 6500cuft since only about 1200ppm needs to be added to reach that, and a 20lb tank should yield about 130000cuft of ideal air over its life..
IIRC, your area is roughly 75sqft (600cuft??), so that would be ~220 total air exchanges if CO2 weighed the same as ground level air..

But this is where need for a meter comes in since CO2 is heavier than air (its specific gravity is ~1.52), and you exhaust from the top.. Its tough to say how much gets exhausted.. Its safe to say that it would last quite a bit longer since exhaust is at the cieling, but there could be a long term buildup differential each day.. The more interior air movement you have, the less buildup will occur obviously.. You wouldn't want that circulation fan blowing it up at your exhaust, and you wouldn't want each cycle raising the level by x ppm unless you had planned on that, and know you'll be staying under around 2000ppm .. This is really kind of analogous to that hvac chat we had in your journal..
 

Stifling

Active Member
Some rough math:
20lbs CO2 = ~10 moles of CO2..
10 moles of any gas will occupy ~8cuft at STP
So diluted to 1500ppm, 1lb of CO2 will create ~5200cuft of ideal plant air.. Actually about 6500cuft since only about 1200ppm needs to be added to reach that, and a 20lb tank should yield about 130000cuft of ideal air over its life..
IIRC, your area is roughly 75sqft (600cuft??), so that would be ~220 total air exchanges if CO2 weighed the same as ground level air..

..


It's been a while since high school, but isn't a mole of CO2 only 44 grams, and not 2 pounds? If so, you'd get about 200 moles from 20 lbs of CO2
 

born2killspam

Well-Known Member
Oops, thanks that 20 in the first line was supposed to be 1..:) Its a loner typo though, the mistake doesn't follow through the math.. Wonder if I can still edit that.. +rep for catching that..
 
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