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Stanwood, Washington

I am considering CO2 for next year but have some doubts about how practical it is. How are you balancing out your CO2 with the need to ventilate the greenhouse during the day. Are you just running the CO2 in the morning and then shutting it off once the temps are high enough to require ventilation or are you running the CO2 all day? If you have roof ventilation will the CO2 hug the ground and stay around the plant or will it all just pretty much dissipate when the vents are open?

9/26/2019 5:22:36 PM

Lymington

We vent at our optimum levels and when the vents are shut we can use CO2 even though CO2 will tend to fall to the ground as soon as you open the vents it disappears very quickly you’ve got it exactly right Stewie

9/26/2019 5:56:48 PM

Connecticut

Captain 97-
Sorry for the delay in a reply.

Both my diary and various Newsletter articles (most recent publication is the GPC newsletter) contain a lot of information about my specific set-up. However, to address some of your questions...

1.) How are you balancing out your CO2 with the need to ventilate the greenhouse during the day.
My elevated CO2 levels (~900-1000ppm) are activated only during daylight hours. When the ventilation system comes on (when temp reaches 85F) the CO2 enrichment system turns off.

http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=305082
http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=303698
http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=303699


2.) Are you just running the CO2 in the morning and then shutting it off once the temps are high enough to require ventilation or are you running the CO2 all day?
While my full enrichment system does turn off at 85F, I did add another system that was "always on" during daylight hours that was set to 400ppm which is the normal atmospheric conditions. What I was noticing is during times of high heat and sun the CO2 levels were dropping so I added another independent system to help ensure the CO2 levels do not drop below normal levels.

http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=308239
http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=308398

3.) If you have roof ventilation will the CO2 hug the ground and stay around the plant or will it all just pretty much dissipate when the vents are open?
I only had vents and an exhaust fan, but CO2 is heavier than air, and I injected it below the leaf canopy and had my sensor right at the leaf canopy. However I can say that CO2 was still being exhausted even with this placement.

http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=304124
http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=306904

Any other questions let me know.

-Matt D.

10/5/2019 2:15:29 PM

Stanwood, Washington

Hi Matt,
thanks for the reply. on average how many hours are you getting before the the vents open up and the CO2 shuts off?

Are you seeing a noticeable difference with the plants and fruit growth?

In my case I will be building a greenhouse myself and I won't have automated venting so I would pretty much need to vent the greenhouse at 8:00 AM 5 days a week when I head out for work. I am not sure that the benefits of the short amount of time the CO2 will be able to be on will be worth it.

10/8/2019 1:07:50 PM