Co2 Increasing at Night

[Minor_Obcession]

Why are my co2 levels increasing at night? This is a new sealed room with a propane generator, split A/C, soil. Co2 levels are maintained during the day at 900-1100, but my ppm rises to 1700-1900 at night. When the levels were set at 900 with a 100 ppm deadband, it was reaching 1700 at night. When I bumped daytime ppm to 1000, nightime levels hit ~1900. What do you think is happening? Any comments would be appreciated. thanks in advance-

Generator- Titan Ares 10
Controller- Titan Atlas 8

Theory A: controller's photocell is faulty
Theory B: microbes in soil are respirating heavily
Theory C: concrete leaching co2
Theory D: plants are giving off excess co2 levels at night

 

[TheArchitect]

Pretty standard, the plants dump it at night.

Put the co2 burner on a timer so it goes off an hour or so before lights out.

 

[Minor_Obcession]

I have ran co2 on several different builds before but never noticed levels this high. In fact, my co2 levels always dropped at night. Maybe it is because this it the first truly sealed room without any cracks. I wonder if there would be a way to correlate a plants needs by the day/night ratio.

Cheers

 

[stoned-trout]

ya that^^^^^

 

[TheArchitect]

I have ran co2 on several different builds before but never noticed levels this high

.

Maybe it is because this it the first truly sealed room without any cracks.

There ya go.

Do you have a carbon scrubber purifying the air since its sealed tight?

 

[Minor_Obcession]

Yes, I am running carbon on recirculation once every three minutes. How might this effect the situation?

 

[TheArchitect]

Yes, I am running carbon on recirculation once every three minutes. How might this effect the situation?

I'd just run it constant, it won't hurt, and it will capture any ethylene build up or most other nasty vocs that can build up in a tighly sealed room.

 

[Minor_Obcession]

I was wondering about this, but doesn't it depend on the type of carbon used? I emailed Can asking if their filters adsorb ethylene and for data to backup their claims if they make any. This is my first adventure with propane instead of co2, so yes, I am a little hesitant of additional factors. Thanks for the reminder!

 

[smurfin'herb]

Pretty standard, the plants dump it at night.

Put the co2 burner on a timer so it goes off an hour or so before lights out.

Another vote for this ^

 

[TheArchitect]

I was wondering about this, but doesn't it depend on the type of carbon used? I emailed Can asking if their filters adsorb ethylene and for data to backup their claims if they make any. This is my first adventure with propane instead of co2, so yes, I am a little hesitant of additional factors. Thanks for the reminder!

No, thank you for the reminder, you do need a particular carbon.

You need carbon with, iirc, potassium permanganate, or an air ionizer.