Onceuponapuff
Member
Hi,
I'm running 4x400W HPS bulbs vertically, just started flowering. During vegging I didn't have a problem with keeping my exhaust fan on during the 6 hours of darkness. I have an electric heater set up right under the intake ducts, and the temperatures always stayed at a perfect range. I also have 4 oscillating fans running 24/7 under each bulb to keep the airflow going, and another fan running at the plants during the light period.
The exhaust is powerful enough to change the air in the grow room about every 3 minutes.
However, 12 hours is a different story - and winter's kicking in. I live in a very cold climate.
Yesterday the grow room temperature dropped to 15.8 for the first time, and so today I turned my exhaust fan off during the darkness period.
For now I'll keep it off and track the changes in humidity and temperature every hour or 2, try to see how often I should turn it on and for how long, I guess it's the best I can do.
Reason I'm posting this is to talk some theory crafting, and to hear what You think.
The plants don't need as much CO2 during the darkness period, and since the lights are off the temperatures aren't a problem either. However, the roots still need Oxygen and the grow room should always have some fresh air coming in. The oscillating fans prevent the air from becoming stale, but still - my question remains, just how much fresh airflow do plants need during the darkness period?
I'd like to set my exhaust fan on a timer, so please throw some opinions my way on how often and for how long it should be on. I have absolutely no clue just how often the Oxygen should be replaced in the grow room.
I'm running 4x400W HPS bulbs vertically, just started flowering. During vegging I didn't have a problem with keeping my exhaust fan on during the 6 hours of darkness. I have an electric heater set up right under the intake ducts, and the temperatures always stayed at a perfect range. I also have 4 oscillating fans running 24/7 under each bulb to keep the airflow going, and another fan running at the plants during the light period.
The exhaust is powerful enough to change the air in the grow room about every 3 minutes.
However, 12 hours is a different story - and winter's kicking in. I live in a very cold climate.
Yesterday the grow room temperature dropped to 15.8 for the first time, and so today I turned my exhaust fan off during the darkness period.
For now I'll keep it off and track the changes in humidity and temperature every hour or 2, try to see how often I should turn it on and for how long, I guess it's the best I can do.
Reason I'm posting this is to talk some theory crafting, and to hear what You think.
The plants don't need as much CO2 during the darkness period, and since the lights are off the temperatures aren't a problem either. However, the roots still need Oxygen and the grow room should always have some fresh air coming in. The oscillating fans prevent the air from becoming stale, but still - my question remains, just how much fresh airflow do plants need during the darkness period?
I'd like to set my exhaust fan on a timer, so please throw some opinions my way on how often and for how long it should be on. I have absolutely no clue just how often the Oxygen should be replaced in the grow room.
