Experts Please Help! Exhaust On or Off during Night Cycle? Co2?

Should i leave my exhaust fans on or off during the night cycle? oscillating fans are on 24/7 inside of my tents. My question is regarding exhaust fans ONLY however. How important is it to move/exchange fresh air through the tent at night or off hours? most people exhaust due to heat and also because plants need fresh air, but is this the case at night too?

its my understanding that mold forms easily at night because plants transpire more causing humidity to rise, so from this info i would consider leaving the exhaust on 24/7/

on the other hand i have been told plants give off co2 at night and that exhausting is just a waste of electricity and co2. i have been told the amount of co2 is minimal at best.

If plants really give off co2 at night do they even use it at night?

solarguy said:

Should i leave my exhaust fans on or off during the night cycle? oscillating fans are on 24/7 inside of my tents. My question is regarding exhaust fans ONLY however. How important is it to move/exchange fresh air through the tent at night or off hours? most people exhaust due to heat and also because plants need fresh air, but is this the case at night too?

its my understanding that mold forms easily at night because plants transpire more causing humidity to rise, so from this info i would consider leaving the exhaust on 24/7/

on the other hand i have been told plants give off co2 at night and that exhausting is just a waste of electricity and co2. i have been told the amount of co2 is minimal at best.

If plants really give off co2 at night do they even use it at night?

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I think you answered your own question. The cost to run an inline fan 24/7 is pretty minimal, compared to bud rot.

i found this online.... http://www.quickgrow.com/gardening_articles/fans_air_movement.html

Fans should also be triggered to vent out warm, humid air and high CO2 levels just after the lights switch off at night. High levels of CO2 are not required at night when the plants are respiring and need to use oxygen only from the air. Condensation, can be a problem at night when temperatures cool and humidity in the air result in water forming on plants and other surfaces. Getting good air replacement or air changes in the first couple of hours after lights go off is one way of preventing diseases such as mildew and botrytis whose spores need very high humidity or free water on the leaf surfaces to germinate and infect the plants. If drier, fresh air is continually brought in so humidity is lowered and condensation does not form, then fungal and bacterial pathogens can’t attack the plants.

yup i sure did, im keeping my exhaust on 24/7. They dont need the co2 they are giving off at night, what they need is oxygen so keeping the fans on will keep bringing in fresh air and preventing mold. thanks.

plants only absorb CO2 at night.

just put the co2 tank or bag or whatever, directly under the foilage so it can evaporate right into the plant

anonymuss said:

plants only absorb CO2 at night.

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ummmmm wrong.

plants reverse their process at night, they give off co2 and take in oxygen.

solarguy said:

plants reverse their process at night, they give off co2 and take in oxygen.

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lol

i saw ur last thread

u really think the room is gonna "stockpile" the co2 the plants give off at night and then use it later to get dense buds

ROFLMFAO

u do know basements / closets / bedrooms arnt air-tight right?

(PS if ur planning on using a cabinet to trap the co2 by turning off the fans, the most u would get is maybe 5 minutes worth of Co2 at the cost of not giving your plants air circulation)

c3 plants absorb c02 while photosynthesising, c4 plants do so during the dark period to use in photosynthesis. Cannabis is c3. Anyway though since you turn on your exhaust during lights on it would be rather pointless to have it off during the dark since your plants use it when the lights are 0n. plus like you said i doubt the amount they would produce would have any effect anyway.

anonymuss said:

lol

i saw ur last thread

u really think the room is gonna "stockpile" the co2 the plants give off at night and then use it later to get dense buds

ROFLMFAO

u do know basements / closets / bedrooms arnt air-tight right?

(PS if ur planning on using a cabinet to trap the co2 by turning off the fans, the most u would get is maybe 5 minutes worth of Co2 at the cost of not giving your plants air circulation)

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that last thread was nothing but a idea, this thread is about the need to exhaust or not at night....two totally different things here.

know your role bitch.

only run the c02 when the lights are on. also you want to run your room temp a little higher. have your exhause fan on a timer to kick off while your co2 admits tell it falls then have it kick back on.

i would only run the exhaust fan at night if your R/H is high. i have mine on a timer and when the ligts are off it kicks on every 3 hours for 15mins just cause i like it that way to say the least. no need to waste electricity right?

after digging into this i feel its best to leave them on 24/7. more air flow = prevention of disease mold etc. Also at night cannabis uses oxygen so bringing in fresh air constantly maximizes that. I find ZERO benefit besides electrical savings to turning off exhaust fans. to me electrical savings isn't worth the problems and or sacrificing yield.

solarguy said:

that last thread was nothing but a idea, this thread is about the need to exhaust or not at night....two totally different things here.

know your role bitch.

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my roll is loling at nubs that buy LED setups and have no clue how to grow.

solarguy said:

after digging into this i feel its best to leave them on 24/7. more air flow = prevention of disease mold etc. Also at night cannabis uses oxygen so bringing in fresh air constantly maximizes that. I find ZERO benefit besides electrical savings to turning off exhaust fans. to me electrical savings isn't worth the problems and or sacrificing yield.

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yeah definitly bringing in fresh air all the time. thats what the central heat and air is for. other to cool the lights or to keep R/H down i dont see a reason to run your exhaust fan 24/7. maybe a intake fan if thats what you use

anonymuss said:

my roll is loling at nubs that buy LED setups and have no clue how to grow.

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, Really?! c'mon man, that wasnt really needed.....
No hard feelings though.

darkdestruction420 said:

, Really?! c'mon man, that wasnt really needed.....
No hard feelings though.

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nah it was needed.

LEDs are actually a good choice for nubs. they use little juice they dont turn ur growspace into saudi arabia and dont totally suck like CFLs.

(not counting those giant umbrella CFLs that hydro stores sell)

i wonder if those led's work well.they dont look that intense

Why do you say cfls suck? HID is for sure the way to go imo but cfls can work fine. I've done lots of cfl growing in the past. 8 26w cfls can get a oz or 2 w/o much effort if you know what your doing.