The facts about CO2 ppm: don't use 1,500!

[FatherEarth]

interesting...

I havent finished reading this thread yet... I have experienced CO2 levels as high as 2000 for nearly the entire grow, day and night fluctuations did occur and a gradual decline until harvest was attributed to the waning of the microbial colonies sources of food... Air exchange was very high but at nigh it was far less maybe a few times an hour. The CO2 was from having large amounts of living soil in a small room. That crop was the start of the heaviest yield era for me. It seemed as though the plants still benefited from the night time co2 levels but without any hard data my report is anecdotal at best. I am currently still using this method and love it...

2.5 grams per watt was encouraging I must say...

Big Soil Little Room

[stc]

Great information.

In Grotenhuis's abstract, it states:
“Super-optimal CO2 did not decrease the number of heads per square meter, but reduced seeds per head by 10% and mass per seed by 11%"

I compare the buds to the heads, and since there is no reduction of heads at super-optimal levels then I assume they are not detrimental to the grower's goal. Unless, seeds are the goal.

My knowledge is limited, thus I may be missing something.

I appreciate the abstracts. You are so correct that it appears there are no studies supporting the 1500ppm assumption.

[jaydeowl]

bump for sticky

[Beavinator]

Man I am so confused about what is the ideal Co2 level. I have been growing for 20 years now and since day 1 I have had it drilled into my brain that you want 1500 ppm Co2. Now Im being told that 1000 is ideal.

[the gnome]

if you've been running 1500ppm it's easy nuff to find out if 1000 is better.
give it a go, after all these years you should be able to tell if it's better-worse or the same

[MediLove]

CO2 too high at night?

Hi and thanks for the great post! I am working on a green house system with CO2 enrichment. I am using a ventless propane heater at night to keep it warm. During the day I can monitor my co2 levels to 1000-1100 but at night when the heater is on my levels get too high around 2200-3000. Is this a major consern. Should I vent some fresh air every few hours. Any advise? Thanks

[the gnome]

your propane heater is definitely adding Co2 to the mix
also @lites out the plants start dumping out their excess of unused Co2.
I peak @1900 ppms during the dump, 3000 is pretty hi.
are the plants doing ok?
the excess Co2 will get taken up when the lites are back on,
unless your seeing plant probs I'd think you'd be fine.
but!
it's hi for us humans, watch out if your in there when it's so hi,
I start feeling tired and get headaches if I'm in there working for a few hours above 1500
a 20 minute break and I feel like a new man

[MediLove]

Thanks for the help, I dont have plants in there yet. Trying to get it all honed in before I put the girls in there. Thanks I will try to vent a bit to keep the levels down. It is not a completely sealed space.

[MediLove]

Have another question about temp when maintaining high CO2 levels. Is day time temp of 90 to 95 really ok? What about night time temp. What is best? Thanks

[Mrrite008]

Have another question about temp when maintaining high CO2 levels. Is day time temp of 90 to 95 really ok? What about night time temp. What is best? Thanks

If explosive growth is what you want, run your room at 85 with an RH of 75% (VPD) + CO2. Keep your Temp and RH as close to these #'s as possible during lights off. Maintain a proper VPD during lights off regardless. Proper airflow both above and below the canopy is important!

[MikeGreat]

What a great thread and what a fantastic contributor to this group Spurr was... Shame that he is no longer here.

[johnyXXX]

Hi guys,
what you write here is really awesome. So I did some change for my girls, but I have some problem.
I had used temperatur 93°F, humidity about 60% and co2 1500ppm and everything was ok. But now when I tried to maintain lower temperatur I cant get under 86°F with turn on humidifier, without them humidity go really high. I have everything right, girls are in basement, colder place in the house, lights are in tubes (box 240*120cm, 2*600w and 2*400mh3 for tubes, 2 for safety reason, in box 1000mh3 out and 500mh3 in). Acording to my calculation everythink is oversize and there is still quiete hit. And from basemnet blow one 3000mh3.
How do you get so low temperatur? Do I have weak fans for the lights? Dp you have any advice?

[epicseeds]

Bringing this thread back to life! Just read it all, thanks so much spurr. It's a shame he has been banned and can't find him anywhere else.

[epicseeds]

Still no activity?

Any consensus on when to cut C02 during flush from a scientific standpoint? Or just let her stay at ~1100 to the very end?

Not looking for antidotal evidence - Spurr was great at leaving sources :(

[Vandenberg]

Useful information

~1,100 ppm~ is a good thing.
Accurate and affordable adjustable CO2 monitor controllers have recently became available (under $250 USD).
It deadzones my Autopilot burner set-up.between 1050 and 1250 ppm
Bump

Vandenberg