Elevating carbon dioxide levels can increase growth speed a great deal, perhaps even double it. It seems that the plant evolved in primordial times when natural CO2 levels were many times what they are today. The plant uses CO2 for photosynthesis to create sugars it uses to build plant tissues. Elevating the CO2 level will increase the plants ability to manufacture these sugars and plant growth rate is enhanced considerably.
For a medium sized indoor operation, one approach is to used CO2 canisters from wielding supply houses. This is expensive initially, but fairly inexpensive in the long run. These systems are good only if your area is not too big or too small.
That being said, does anyone here have any experianced in using bottled co2 for growing?
What flow rate did you use for what size room?
iv read as much as i can find and fow rate is still unclear to me, obviously to much co2 can be bad , to little will be ineffective

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any info would be much appreciated