Carbon dioxide levels can increase growth speed a great deal, it can even double it. The plant uses CO2 for photosynthesis to create sugars it uses to build plant tissues. CO2 level will increase the plants ability to manufacture these sugars and plant growth rate is enhanced considerably.
CO2 is most usable for flowering, but can be used during veg aswell.

The basic CO2 tank system looks like this:

20 lb tank $ 100
Fill up $ 15- 20

You can buy or lease cylinders from local welding supply houses. If asked, you can say you have an old mig welder at home and need to patch something up.

For a small closet, one tank could last 2 months, but it depends on how much is released, how often the room is vented, hours of light cycle, room leaks. This method may be overkill for your small closet.

It is good to have a small constant flow of CO2 over the plants at all times the lights are on, dispersing directly over the plants during the time exhaust fans are off. When the light is off you don't need CO2. When the fan is on for venting, CO2 should be shut off.

i used to use it but it doesent make that much of a diffrence

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Co2 is amazing you can see the results in my grow journal ..linked below in my sig...

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4x1000 +co2+9 strains+=good times 8x1000 watts CO2 Hydro grow Jacks Back

It may be a good idea to turn off CO2 2 weeks before harvesting. high CO2 levels in the grow room near harvest time lower potency.

How effective added CO2 is depends entirely on your grow room, like weedyoo it won't always make a significant differance, and sometimes it won't even make a noticable one. CO2 is a great addition to the growroom and can increase growth rates quite a bit...under the right conditions. Kits are expensive so it's best to know if it's going to be worth it ahead of time, and it's pretty easy to find out.

The reason weedyoo, and most other growers don't see the full advantages is because in 99 out of 100 growrooms the CO2 concentration is not what's holding the plant back. There is always a photoinhibitor so to speak, a limiting factor in your growroom...for most of us more lights would be a far better investment than CO2 supplementation. You really have to consider what else might be limiting your plants growth before you can expect to see any change from more CO2. Chances are for most growers CO2 isn't going to provide a significant growth rate increase, first you have to perfect everything else...lights, ferts, temps.

I don't mean to disagree with catpiss at all, I just think growers (espescially new growers) should be aware that there are a few things they need to worry about before CO2. To see the any real improvement from additional CO2 you should already have at least 100+ watts per sq. foot in your flower room IMO.

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[QUOTE=Hubert;2666804]How effective added CO2 is depends entirely on your grow room, like weedyoo it won't always make a significant differance, and sometimes it won't even make a noticable one. CO2 is a great addition to the growroom and can increase growth rates quite a bit...under the right conditions. Kits are expensive so it's best to know if it's going to be worth it ahead of time, and it's pretty easy to find out.

The reason weedyoo, and most other growers don't see the full advantages is because in 99 out of 100 growrooms the CO2 concentration is not what's holding the plant back. There is always a photoinhibitor so to speak, a limiting factor in your growroom...for most of us more lights would be a far better investment than CO2 supplementation. You really have to consider what else might be limiting your plants growth before you can expect to see any change from more CO2. Chances are for most growers CO2 isn't going to provide a significant growth rate increase, first you have to perfect everything else...lights, ferts, temps.




nice point hubert. Thanks for the info.

i would only use CO2 if the grow room was huge. other than that i prefer to veg outdoors where its plentiful

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Different parts of the world has more co2 in the air than other parts of the world. Where have you grown outdoor.

Wow some of the post amaze me. Not to discredit anyone, every situation is different but from my experience CO2 is the greatest thing since sliced bread. I grow indoors and for 3 years didnt use CO2 and this last harvest we put in an environmental control system linked to a 50lb CO2 tank and regulator. What this does is keep the room at a constant 1500-2000 ppm of CO2 and YES MY PLANTS GREW FASTER AND DOUBLED THERE SIZE compared to previous grows.(2ft plants in about 3 weeks) If your enriching your room manually it will not work the same. YOU NEED CONSTANT CO2 LEVELS OF 1500ppm to see sufficient results. And this is applying to INDOOR grows not OUTDOOR. For the record my room is 8x8 so no it doesnt have to be a HUGE room to make it worth your while trust me on this one. Google this stuff and do some homework, you may be amazed at what youll find

And catpiss you are correct as well. If your growing with a small 400 watt light or some cfl's its not gunna be worth it. But if you have stuff down (decent light, constant temps, perfect humidity) CO2 will seriously pump your plants like no other. We did deep water culture for a year with house and garden nutes. Had perfect temps, 1000w lights, perfect humidity, babied them everyday, and they still didnt do what I got out of this last harvest (this last harvest was in soil not hydro so that should tell you something)