Adding Co2

[Zeropest]

Co2 increases yield and makes the plant healthier. Free Co2 is great at 1500ppm but expensive. Cannabis can separate Co2 from Carbonic acid. It can get upwards of 80% of its needs. Carbonic acid is water and Co2. So instead of adding Co2 to the space. Has anyone tried a drip irrigation. You inject the Co2 into irrigation lines.

[Toker1]

Thought of this myself before. Never tried it though. I’m going to bump this! I’m interested to see what others have tried.
I think co2 can only be taken in through the stomata located in the leaves though.

[Canuck147]

I give em Co2 from yeast.
Body temperature water with honey or sugar and yeast. Works for a few days then starts fermenting.
Costco size container of yeast is cheapest.

[LurkingInTheGrass]

Nice idea

Oxygen at the roots, CO2 at the leaves

When I'm cloning/sprouting in a dome, I will fill the dome with my with breath. It seems to encourage growth (CO2 and humidity)

[NAKEDGARDENER]

The problem with high amounts of c02 at a ppm of 1500 is that you must have that space isolated from your own breathing air, I think I am correct in saying that you do not want to be in an out of control c02 environment for very long. That being said there are products that do deliver c02 in an uncontrolled method and are placed into the grow space but as I understand it, high levels of Co2 also require higher photon delivery or in other words, a lot of high light output for those levels to have much of an effect.

I have seen a friends automated co2 system and he has taken it out since he says he has seen little advantage of running it. But I’m sure many will also say that your buds are fatter and larger or they smell or taste betterI personally haven’t seen any evidence of this yet. Sad to say.

[DrPhoton]

Co2 is obtained through the stomata of leaves. Most plants are not co2 limited until they reach the point of saturation where light levels are beyond what is possible for leaves to process at the current ambient level (around 400ppm). This has been shown by chandra to be around the 1000umols, where plants start becoming co2 limited. But it is more beneficial to use co2 supplementation when average light levels reach between 1000-1500umols as this is the point where severe co2 deficiency occurs and photosynthetic efficiency declines. Many might assume that using co2 will allow one to bring their lights closer and as a result, increase light delivery to plants. But this is not the case as increased light proximity does not provide more light to plants, due to the reason that their is no significant loss of light when light passes through air as a medium.

Where co2 supplimentation is most beneficial, is when more powerful light sources are used that is typically too strong for a typical sized grow area. For example, in a 4x4 where a 600w HID light is used. This provides an average light level of around 740umols of photon density. Which is right on the point where photosynthetic efficiency really starts to decline. So 600w in a 4x4 is the max you would want for that size grow area. Where as a 1000W DE HID, will have a average 1140umols of photon density. Way too much for a 4x4. However, with co2 supplementation, you can use these higher discharge light sources as the plant no longer will be co2 limited at these higher light levels.

[NAKEDGARDENER]

Makes perfect sense. Thank you DrPhoton

[DrPhoton]

No worries

[kingfish]

DrPhoton, I have a 4x4x7 tent and been using 1000w HPS since day one. I've been growing for about 10 years. Have I been missing something? I always thought I grew some pretty decent buds.

[DrPhoton]

No one said you cant do it, but its not as efficient as you would have your fixture higher in order to prevent photodamage. Creating radiative and reflective losses. Which if the fixture was used in a more appropriate sized environment, would not be subject to these losses. I have seen many who use 1000w in a 4x4, not yield what they should when used in a better suited environment.