Co2 with lights out.

I know this has been covered, but what if any effect will co2 have if you run it during the sleep portion of 12/12? My grow room temps won't allow me to use it during lights/on. Thanks in advance.

What are your grow room temps with lights on? CO2 generally does fine with high temps.

It gets in the low to mid 90's.

co2 will have ZERO effect with lights out! the plants take it in during photosynthesis and when photosynthesis is not working....no co2 is needed by the plant.

regarding heat co2 will make your plants able to survive in higher temps for example ive seen a grower who had temps around 80 and with introducing co2 at 1500 ppm he was able to have his plants survive in the high 90's fine. I have even heard of growers growing in 100+.

CO2 works better at high temps
as a matter of fact its almost worthless at low temps. high 80s is preferable but in your case with temps in the mid 90s they are going to grow alot better with CO2 than without.
as for CO2 with lights out / the plants stop transpiration when lights are out there for cannot use CO2

storm22 said:

regarding heat co2 will make your plants able to survive in higher temps for example ive seen a grower who had temps around 80 and with introducing co2 at 1500 ppm he was able to have his plants survive in the high 90's fine. I have even heard of growers growing in 100+.

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Thanks for the help, all the books that i've read say that the plants will shut down in anything higher than 90. Currently I keep the door cracked about an inch, and I have a squirrel cage exhausting the heat. I'm just wondering if co2 will make that much difference in the yeild, and is it worth risking my babies? Oh, by the way + rep to everyone who responded.

kmo8762 said:

It gets in the low to mid 90's.

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get thou's temp's down or don't even try co2..hell just get the temps down...yours plants wont grow as well in that high temp condition. try and keep it below 85.

yeah, a higher co2 concentration allows the plants to tolerate higher temps. i've read this too. though you should try to exhaust some of that heat.

royalgreen said:

get thou's temp's down or don't even try co2..hell just get the temps down...yours plants wont grow as well in that high temp condition. try and keep it below 85.

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No, no, no, currently my temps are 72-78 degrees. I'm just wondering if it's ethical to risk higher temps to justify co2?