jijiandfarmgang
Well-Known Member
I've been saying this for a while, but for some reason instead of intelligent debate people many people just say I'm flat out wrong.
Everyone keeps spouting "I heard you need airflow 1-5 times per minute to keep CO2 levels high." Or "you need plenty of air exchange for CO2", or "plants need fresh air" etc.
In my experience this just isn't true. Let me get one thing straight. I'm talking about "NEED" not "IDEAL".
In general (In the typical indoor growing world) its more important to focus on environmental temps, and humidity. If you need to exchange air in your room say every 2 times a minute to keep temps down, then you should do it. But if your intaking very cold air all the time and using heaters, because you think the plants need fresh air, your doing yourself a disservice.
A couple years ago (I can't remember the numbers) I tested a 3k indoor grow room with a CO2 monitor. It was in a home that was drafty (3/4 inch gap underneath door, no vapor barrier or tyvek, probably not much insulation). This room was sealed with no CO2 gen. At all times, this room had a decent amount higher CO2 content than outdoors.
Recently wanting to prove a point I wanted to do an more thorough job and datalog an outbuilding grow. I'm running into a few issues datalogging but here are the inital results.
4k grow room built in a barn. Drywall, and fiberglass insulation. No caulking, No vapour barrier (this may or may not be important). The room is sealed in winter. Entering the room once per day for tending, watering. High of above 2000 ppm while in the room (this number is unimportant as I was near the meter, while it was initializing). Now 24 hours later I entered the room and checked the meter 441 ppm CO2. When I checked memory for the minimum recorded CO2 it was 423 ppm CO2.
- Jiji
Everyone keeps spouting "I heard you need airflow 1-5 times per minute to keep CO2 levels high." Or "you need plenty of air exchange for CO2", or "plants need fresh air" etc.
In my experience this just isn't true. Let me get one thing straight. I'm talking about "NEED" not "IDEAL".
In general (In the typical indoor growing world) its more important to focus on environmental temps, and humidity. If you need to exchange air in your room say every 2 times a minute to keep temps down, then you should do it. But if your intaking very cold air all the time and using heaters, because you think the plants need fresh air, your doing yourself a disservice.
A couple years ago (I can't remember the numbers) I tested a 3k indoor grow room with a CO2 monitor. It was in a home that was drafty (3/4 inch gap underneath door, no vapor barrier or tyvek, probably not much insulation). This room was sealed with no CO2 gen. At all times, this room had a decent amount higher CO2 content than outdoors.
Recently wanting to prove a point I wanted to do an more thorough job and datalog an outbuilding grow. I'm running into a few issues datalogging but here are the inital results.
4k grow room built in a barn. Drywall, and fiberglass insulation. No caulking, No vapour barrier (this may or may not be important). The room is sealed in winter. Entering the room once per day for tending, watering. High of above 2000 ppm while in the room (this number is unimportant as I was near the meter, while it was initializing). Now 24 hours later I entered the room and checked the meter 441 ppm CO2. When I checked memory for the minimum recorded CO2 it was 423 ppm CO2.
- Jiji
but yes I know what it takes to replace my rooms air. "My" rooms co2 availability level will peak at the time of replacement while the rooms temp will be at its lowest as the air bringing in the co2 is cold. Directly after replacement my room almost immediately returns to its normal, pretty constant temps and starts using this new co2-filled air. What we want to know is how long before Co2 levels drop to a level below what the plants "need" and we need to replenish with new air again. The less I need to replenish with this cold air the better. So, we are mainly talking co2 availability, not use.