Ventilation fans question

I have an intake and exhaust fan in my tent. To those of you growing in tents, how much of the day do you keep your ventilation fans on? Do you change it based on what stage of growth they are at? Ive been running mine 24/7 but ive been seeing people talking about turning them off/down at night or running them one hour on one hour off. Also people saying they got issues from humidity and powdery mildew when they turned their fans off. Curious what you guys are doing. Wondering if mine would be better turned off part time.


Airflow is your friend. Run them 24/7 regardless of stage. It is important for CO2 replenishment and to mitigate mold.


Mine shut off one night cycle. I opened 4x4 tent to tropics jungle dripping all-over.
Tent & leaves drip.
Oscillating tower fan used 24x7
Exhaust some, always.
Intake static unless moving high CFM
Intake&Exhaust temp and humidity control.

Remote monitoring allows me furlough and sleep at night.


24/7 through out grow , Also in flowering stage with large colas I will increase speed on Exhaust fan to pull more air flow.


The first thing I learned, well after the seed germination, was air flow, air flow, air flow. Ventilation fan running always to exchange old, stale air in tent with refreshed air coming in from lung room. Clip on fan attached to the tent pole for moving the air around inside of the tent, not aimed AT your plants.


Unless you have high RH issues/mold concerns…then blasting them directly with air consistently could be better than the alternative :wink:


Are your intake/exhaust fans operating through a n environment system such as a vivosun or a/c infinity controller? As an example, I have my duct fan programmed to run continuously as airflow is really important, but it will automatically increase its output if the humidity or temperature reaches the set limits I’ve programmed in. Such as your tent getting too hot or too humid… This feature has save me a few times

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Intake at ground level, exhaust at top of tents 24/7


I run mine 24/7