How much fresh air do plants need at night?

Ventilating a room serves 3 purposes.

1) to cool the room
2) to lower humidity
3) to get fresh air

Let's forget about number 1 and number 2.

How much fresh air exchange is optimal for plant growth at night?

Helmut79 said:

Ventilating a room serves 3 purposes.

1) to cool the room
2) to lower humidity
3) to get fresh air

Let's forget about number 1 and number 2.

How much fresh air exchange is optimal for plant growth at night?

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i exchange none at night. some people exchange at night for critical reasons (rh or temps high).
thought you were considering co2?

(I'm considering different things. Trying to understand which solution suits me better)

As I understand, plants don't need Co2/fresh air when lights are off?

Ventilation at night is mainly to reduce RH, right?

Helmut79 said:

(I'm considering different things. Trying to understand which solution suits me better)

As I understand, plants don't need Co2/fresh air when lights are off?

Ventilation at night is mainly to reduce RH, right?

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As well as a dehumidifier which is a must with co2

"Fresh air" is just air with co2 to replenish whats used. Plants dont need fresh co2 at night so theres no need to exchange the air...
Dehumidifiers are clutch btw.

Sir KK

The plant continues to use oxygen during the night to burn sugars for growth. It does this during both the night and day and releases CO2.

I think OP is asking how much oxygen the plant needs, or how fast CO2 accumulates at night if you don't remove it. I don't know the answer to this actually.

Ventilating the room at night helps with taking out the co2 the girls release at that period, this then makes way for fresher air n most importantly oxygen to be more available to the plant. Remember the roots are at their most active at nights whilst during the day the foliage plays major role and roots need oxygen, u need an oxygen enriched room at night so to not have heavy co2 fill the area and be an obstacle in airflow rate it's best you ventilate.

churchhaze said:

The plant continues to use oxygen during the night to burn sugars for growth. It does this during both the night and day and releases CO2.

I think OP is asking how much oxygen the plant needs, or how fast CO2 accumulates at night if you don't remove it. I don't know the answer to this actually.

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Plants use co2 above the root zone and oxygen in the root zone.

Plants use CO2 to make sugars in a process called photosynthesis, but they use O2 for respiration (burning those sugars for immediate energy)

During the day, it seems like the plant is not using oxygen, but that's only because it's producing more than it's using.

CouchlockOR said:

Plants use co2 above the root zone and oxygen in the root zone.

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BigMaineyXL said:

Ventilating the room at night helps with taking out the co2 the girls release at that period, this then makes way for fresher air n most importantly oxygen to be more available to the plant. Remember the roots are at their most active at nights whilst during the day the foliage plays major role and roots need oxygen, u need an oxygen enriched room at night so to not have heavy co2 fill the area and be an obstacle in airflow rate it's best you ventilate.

Click to expand...

Good post. So now i have to take my fucking exhaust off my controller and maybe put on a fucking push button timer? Had my exhaust hooked up to cooling port of controller in case something happened and temps breached. Im my experience the ppm's get pretty high during night cycle from the light cycles usage of co2. Releasing more from leafs was always my thought. Any how good post, I'm going to do more reading.

a mongo frog said:

Good post. So now i have to take my fucking exhaust off my controller and maybe put on a fucking push button timer? Had my exhaust hooked up to cooling port of controller in case something happened and temps breached. Im my experience the ppm's get pretty high during night cycle from the light cycles usage of co2. Releasing more from leafs was always my thought. Any how good post, I'm going to do more reading.

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No problem always will give best advice to my knowledge and as you are going to do, I'll be continuing reading and researching into plants and functions plus plenty other craps that seem never ending lol.

If your environment doesn't change and all is the same the only reason for a dramatic change in temps would be humidity being high if ventilating this shouldn't change much. Your plants produce foliage from no where just Bush out and humidity rises and soon follows heat and ermm one of Ur equipments breaks or something becomes faulty. Other than that theres not a lot I can think that would make Ur environment change dramatically and from pretty good go bad it's not possible if all variables remain relatively stable.