Ok, put down the binger or vape as this is a semi technical post
Theres a few threads on this issue here regarding running fans 24/7, and not one of them discusses why a fan on at night
could be harmful, so I'll address and explain why. (Remember, I say COULD, because it all boils down to ambient conditions and is entirely based on humidity or established pathegens aka mold and such on the plants)
There's really no reason to leave the fans on constantly at nightime. (Intermittent at night is best in all situations unless the humity is >70%, then the fan SHOULD NEVER EVER be run at night unless you have a dehumidifyer or running sulpher dioxide to curtail established mold, mites or pathegen issues, I'll explain more in detail below)
Having a fan set to a timer at night is ideal, set to a few minutes an hour or so then turn off until the lights come on. Reason for intermittent fan use is so the lenticels can absorb 02 at night and 03 and 02 during the day aka 'port vessel or breathing apparatus (lenticel) on the plant, but the fan on 24/7 is popular, it's not necessary, especially if the humidity is <70%, more on that below. Also 99 times out of 100, the lenticels are where mold, fungi and pathegens usually enter the plant to make it ill
Plants close their stomata at night to avoid water loss, combined with no nightime photosynthesis taking place
Theres a few tidbits of info regarding humidity and constant fan use day and night, 50% humidity is ideal, if your nightime humidity is say, 70% or more, a dehumidifyier is what you really need,
why? because a fan running continuously at night can actually be more harm than good if the humidity is to high, Once mildew is established, fans may actually spread spores throughout the grow room, generally, at night.
It's ok to run the fans 24/7, just make sure the humidity is in check, because if not, as mentioned above, it actually may be a bad thing to do. Now you know what I know
PS, If you find this info useful, give me a rep. Some people still think I'm a noob. Well I am a noob and always learning new things, this is why I'm here.
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