Proper Night Co2 Levels & Exhaust/intake With Co2 In Sealed Rooms?

[greendarknight]

I have done a lot of research on the farm and read a lot of other information about proper co2 levels during the day and at night. From all info I derived that day levels should be 1000-1200 and night time levels should drop to 700-800 to allow the plants to respirate properly and encourage optimal growth (since we all know plants grow at night).

We run all of our rooms sealed, and levels never really drop under 1000 at night.

We do not air cool at all so we have not run any intakes/exhaust fans since we switched from air cooled lamps.

So the question is 2 part...

Do you believe that dropping levels is concretely beneficial?

If you do, do you exhaust out and intake fresh air once the lights turn off or just intake or exhaust?

I read that if you only exhaust, you do not need to intake air but this doesn't make sense to me, don't want to take air out of the room to not replace it.

 

[motherlode]

at night plants breath in o2 and release co2 - so with levels of 1000 or higher you are stressing them technically speaking

you can not exhaust a room without intake - passive or otherwise - it is not possible

if you have only intake that will give you positive pressure on the room and make it smell outside

its not a bad idea to have exhaust on a controller in case of humidity spikes or heat build up due to a failed ac and exchange the air once to day to avoid buildup of Ethylene

 

[noone88]

Are you using LP CO2 generator?

 

[greendarknight]

at night plants breath in o2 and release co2 - so with levels of 1000 or higher you are stressing them technically speaking

you can not exhaust a room without intake - passive or otherwise - it is not possible

if you have only intake that will give you positive pressure on the room and make it smell outside

its not a bad idea to have exhaust on a controller in case of humidity spikes or heat build up due to a failed ac and exchange the air once to day to avoid buildup of Ethylene

That is what I figured; that you have to replace the air you take out.

Are you using LP CO2 generator?

Yes, I am.

 

[FooDoo]

You want night time co2 around 500 actually.

What I do is sandwich a timer between my tank solenoid and my environmental controller. The controller won't turn co2 off until lights go off, however , the timer kills the co2 tank 2 hours before lights off.

Those two hours of lights on but no co2 allow the plants to bring ppm down to 300/400. Then lights turn off, they exhaust a bit of unused stored co2, and ppms settles around 600-700 for the night.

That's the best I've been able to do without an intake and exhaust on my sealed room

 

[noone88]

There seems to be an issue with sealed rooms, minisplits, and LP burners. It's either incomplete combustion, ethylene gas, and/or bad LP. It causes leaves to brown, starting from the tips. It looks like a Ca/Mg deficiency, but it's not. I would watch your plants carefully to make sure you're not getting this problem.

To answer your questions, I do try to keep the CO2 levels at or lower during the night cycle. To effectively exchange air, you need an intake and exhaust. However, I am "getting by" by turning off the burner and leaving the door open during the light cycle for about 2 hours.

 

[toxic1]

i run a sealed room(tanks) and my night time co2 levels usually reach around 2000 ppm. when the lights come i just open the door for about 20-30 minutes to let the levels come down to 1000 and it also lets in fresh air.

 

[motherlode]

i run a sealed room(tanks) and my night time co2 levels usually reach around 2000 ppm. when the lights come i just open the door for about 20-30 minutes to let the levels come down to 1000 and it also lets in fresh air.

why? what controller do you have that pumps co2 with the lights off?

seems like a huge waste

 

[toxic1]

i have a sentinel. it doesnt run when the lights are off. the co2 levels rise because plants release excess co2 at night

 

[FooDoo]

when the lights come i just open the door for about 20-30 minutes to let the levels come down to 1000

Why wouldn't you do this right when the lights turn off instead?

There's no need to open a door with lights on, plants will take in that co2 and bring it down themselves

 

[toxic1]

because when my lights go off my levels are 900-1100 ppms.

 

[motherlode]

damn mang yer girls be doing some heavy breathing at night - lol

 

[toxic1]

it only gets that high mid to late flower :p

 

[Myco]

If you're that concerned about it, rig up a fan/timer and exhaust the room at night, with a carbon scrubber if smell is an issue. It wouldn't take much aid movement to get levels back down to ambient or slightly above.

I run sealed at 1200ppm max, my levels drop to 500-600 at lights off with no exhaust...

 

[FooDoo]

because when my lights go off my levels are 900-1100 ppms.

OK... Doesn't make sense or answer my question