CO2

[Ninja420]

Can someone explain the basics of adding CO2? Will it shock/be stressful to the plants if they weren't grown with CO2 in veg. and placed in a flowering room that has CO2? Do you turn off CO2 the last 2 weeks? Any help is greatly appreciated.

Ninja

 

[Lazyman]

Can someone explain the basics of adding CO2?

Yes, CO2 at 1500 PPM will make plants grow faster than at regular atmospheric conditions (300PPM) as long as all other systems (nutes, light, water) are at optimal levels. Temperature should be increased to 85* with lights on to encourage plants respiration. Yields are usually increased by 20-30% if all goes perfectly.

Will it shock/be stressful to the plants if they weren't grown with CO2 in veg. and placed in a flowering room that has CO2?

No, this is common.

Do you turn off CO2 the last 2 weeks?

No, I would let it run until you chop. Nothing saved by cutting it off IMHO.
Just turn it off at night. You should be running a completely sealed room with AC, no grow room air should be ducted outside at all if using CO2. If you're using air cooled lights, pull air from outside, then pump it back outside so it never touches the "room" air.

 

[Ninja420]

Thanks a lot for the help.

 

[Perpetual Nooch]

I would vent the room during lights off. Use a timer for the vent fan so it is only on during the dark period.

Use this to calculate your flow meter setting.

http://www.hydroponics.net/learn/co2_calculator.asp

 

[Eminem]

I would vent the room during lights off. Use a timer for the vent fan so it is only on during the dark period.

Use this to calculate your flow meter setting.

http://www.hydroponics.net/learn/co2_calculator.asp

Theres no reason to vent the room at lights off if temps and humidity are in line.


Not many growers use CO2 during veg so that is fine

I have recently learned that CO2 during the last 2 weeks may cause your buds to not ripen on time. Something about Co2 slowing down Ethylene? It was explained in my thread if you want to look for it, the last 3-4 pages.