New Grower Let's Talk CO2 (Tank Fed)

[Trapper]

In my current grow space I average around 515 ppm CO2 and when I've been working in the room for awhile it easily rises up to 1400-1500 levels depending on my proximity (and drops when I leave.)

Due to your lungs converting oxygen to CO2? (breathing)

 

[Muddy]

Yep, from exhaling. Mine also rises when I'm working in there. Last harvest with my friend and I in there all day trimming and manicuring, it got up to 2,800 ppm from a starting level of around 500. I've even given though to just throwing a couple of illegals in there and just let them breath to keep the levels up. :brow:

 

[pop22]

Not a tank system, no. I ended up using a couple exhale bags for my first grow. I didn't have exhaust in that grow just a small fan drawing a bit of fresh air...
I think it helped....the plants need CO2 to convert and when they produce oxygen in a basically closed cab, the O2 needs to be replaced with more fuel for
photosynthesis.

CO2 is heavier than air, so in a closed tent, if you keep your exhaust port higher than the bottom of the tent (which you should to dissipate heat, anyway)
you won't expel the CO2 before it has a chance to help the process.

And if you have an ambient RH% around 25-35%, It can help bring that up a bit while controlling temps. my 2cents.

Ok, wondering, how do you keep a small space at the right temp? If all your trying to do is keep a reasonable amount of CO2 available, but for those striving for the 1000- - 1500ppm of CO2, the plants can't use it unless the temps are high. And if your plant are expiring water along with the O2, how do you have such a low RH? 2 white widows in my 4'x8' space could raise the RH 10-15% easily when maintained at 73F.

 

[Trapper]

I definitely saw RH spikes while the plant was transpiring....

The Low RH is a component of living in the Southwest.

As to temp, a dance between what the lights are putting off vs. what you're removing with exhaust fan speed and filter position...as well as what and how you are drawing in cool air (intake).

 

[Muddy]

Ok, wondering, how do you keep a small space at the right temp? If all your trying to do is keep a reasonable amount of CO2 available, but for those striving for the 1000- - 1500ppm of CO2, the plants can't use it unless the temps are high. And if your plant are expiring water along with the O2, how do you have such a low RH? 2 white widows in my 4'x8' space could raise the RH 10-15% easily when maintained at 73F.

One of these works well at maintaining the temperature. http://www.qcsupply.com/commercial-...mount-variable-speed-controller-110-volt.html. Keeping the RH in check is almost impossible without a dehumidifier. I don't have one in either of my small auto spaces and have run into mold issues from high humidity. Even in my hydro room, where I do have a dehumidifier, it runs almost continuously.