Question on CO2 in sealed rooms???

[moses wellfleet]

i recently changed my rooms to fully sealed ie i removed all extraction and intake fans and ducting and introduced bottled CO2. it seems quite a few people have been changing to this system lately.

my motivation was purely for security reasons, avoiding venting cannabis odour to the entire neighbourhood. any increase in yield would have been an added bonus but was not my primary goal.

the problem is i have been experiencing extreme chlorosis in my flowering room with fan leaves turning almost white and leaflets on the buds dying and going brown. CO2 levels are on average 1200ppm, my room is a perpetual Sea of Green set up with weekly harvests so there are plants in many different stages of development.

when the lights come on i notice that the CO2 level is 2600ppm so it is obviously building up during the dark cycle.

i would like to hear from other sealed room growers how they have set their rooms up and what levels of CO2 they recommend?

also is it actually possible to permanently run a fully sealed operation or is ventilation always necessary at some point?

 

[Guest 18340]

Plants give off co2 when lights are out, thats why the levels are so high when the lights first come on.
I run fully sealed as you described and I set my co2 system to come on about an hour after the lights come on, to give the plants time to use up the co2 they produced while lights out.
What part of the plant is experiencing chlorosis?
My room is permanently sealed, no air in or out except for when I open the door to go in the room, which is a few times a day.
Btw, I set my co2 to come on @700ppm and off @900ppm.

 

[dragunn]

the exact same thing happened to me.switched to sealed room.set ppm at 1000.sentinal controller.a week latter all my plants had major yellowing.

dropped to 500 ppm.color slowly came back.slowly increased my ppm to 700 the next 10 days.yellowing started coming back.dropped back down to 600 ppm.color came back.im staying there for now.

my controller must be off.gonna wait till i harvest and re-set it.

very pissed off a new controller out of the box could be off.

 

[moses wellfleet]

Plants give off co2 when lights are out, thats why the levels are so high when the lights first come on.
I run fully sealed as you described and I set my co2 system to come on about an hour after the lights come on, to give the plants time to use up the co2 they produced while lights out.
What part of the plant is experiencing chlorosis?
My room is permanently sealed, no air in or out except for when I open the door to go in the room, which is a few times a day.
Btw, I set my co2 to come on @700ppm and off @900ppm.

thanx for your reply mate... do you have a way of measuring your CO2 levels when the lights come on? i would like to know if there are other growers who have high levels like mine , 2600ppm during the dark phase but they havnt experienced any problems?

if this is the case then i know that the leaves yellowing up is caused by some other issue.

in the mean time i think i will drop to 900ppm and see how it goes

 

[Guest 18340]

I don't measure my co2 levels, i let the controller handle that and turn on/off as programmed.
But, they do make kits to test co2 levels. http://htgsupply.com/Product-CO2-Tester-Kit.asp

 

[budleydoright]

Co2 sensors are sensitive to shock and vibration and will drift during storage.

If your sensor uses auto calibration, it is likely out of calibration. ABC requires that your room drop to ambient outdoor levels regularly. If it only drops to 600ppm at night, the controller will think 600 is 400 and continue to try to correct for the sensors drift.

 

[moses wellfleet]

Co2 sensors are sensitive to shock and vibration and will drift during storage.

If your sensor uses auto calibration, it is likely out of calibration. ABC requires that your room drop to ambient outdoor levels regularly. If it only drops to 600ppm at night, the controller will think 600 is 400 and continue to try to correct for the sensors drift.

yes you make a good point i have had calibration issues... i am using the ecotechnics evolution complete kit.

can anyone direct me to a thread on sealed rooms i havnt found any using the search function?

 

[mg75]

do you think it is only the co2? or might it be pests, root issues, ph issues?
did you try raising your lights? are the plants furthest from the lights doing better?

i really don't think you are poisoning them with bottled co2. you might have co2 shock, but that results more in stunting than leaf death.

are you using air pumps for a reservoir?

 

[Phillthy]

i have not seen this behavior in the sealed environment but have heard of others with similar issues. if your plants were not in a sealed and co2 supplemented environment previously and are in now then you may want to gradually up the co2 levels from say 400ppm. other than that i can only say that you could raise your lights up a bit and give them a few days to adjust as well.

 

[moses wellfleet]

i have not seen this behavior in the sealed environment but have heard of others with similar issues. if your plants were not in a sealed and co2 supplemented environment previously and are in now then you may want to gradually up the co2 levels from say 400ppm. other than that i can only say that you could raise your lights up a bit and give them a few days to adjust as well.

thanx for your reply phillthy. in your room do you let the CO2 build up during the dark cycle?

 

[budleydoright]

My Co2 drops to close to ambient levels before my lights come on.

 

[LEGI0N]

With the addition of CO2 you need to up your nutrients as well. This is like adding more fuel with out more air to your motor. They go hand in hand. Up your nutes and I bet you'll see things take off.

 

[moses wellfleet]

With the addition of CO2 you need to up your nutrients as well. This is like adding more fuel with out more air to your motor. They go hand in hand. Up your nutes and I bet you'll see things take off.

i never did this nutes are exactly the same as i had all along, i am using organic soil with compost tea and i am not even sure this technique is compatible with CO2 enrichment?... your line of thinking makes sense though!

the only way i can think of to lower CO2 levels during the dark cycle and still keep things sealed would be to circulate the air from the flowering room through the veg room where the lights are on and let the veg plants use up the CO2 produced by the flowering plants?

 

[Phillthy]

to be honest i have no idea what my levels are during lights out. i do know that the burner kicks on as soon as the lights do and it is set to 1000ppm. hope that helps.

 

[Guest 18340]

the only way i can think of to lower CO2 levels during the dark cycle and still keep things sealed would be to circulate the air from the flowering room through the veg room where the lights are on and let the veg plants use up the CO2 produced by the flowering plants?

How high can your co2 levels possibly get when the lights are off that you'd go through the trouble of circulating the air into another room?
Plants give off co2 when the lights are off, but it's no wheres near enough to do any kind of damage or necessitate venting. I can assure you of that from experience. Unless I'm misunderstanding what you're asking (Which is completely possible, because I'm stoned all day)

 

[moses wellfleet]

How high can your co2 levels possibly get when the lights are off that you'd go through the trouble of circulating the air into another room?
Plants give off co2 when the lights are off, but it's no wheres near enough to do any kind of damage or necessitate venting. I can assure you of that from experience. Unless I'm misunderstanding what you're asking (Which is completely possible, because I'm stoned all day)

that answers my question perfectly. so sealed room users generally do not worry about the CO2 build up during the dark phase?

the more i think about it legend is on the money. i need to up my nutes the symptoms do look to me like a nute deficiency.

 

[Phillthy]

to be honest i have no idea what my levels are during lights out. i do know that the burner kicks on as soon as the lights do and it is set to 1000ppm. hope that helps.

i forgot to mention that i have a shared veg and flower space divided and connected via vents. after lights out in flower where the co2 sensor resides, veg is still lit for several hours using what co2 would be left in the room.

 

[moses wellfleet]

i forgot to mention that i have a shared veg and flower space divided and connected via vents. after lights out in flower where the co2 sensor resides, veg is still lit for several hours using what co2 would be left in the room.

that is exactly what i was planning. if you can use up the left over CO2 then your tanks will last longer... thanx phillthy

 

[moses wellfleet]

these are the symptoms. i am sure that legend has called it right

 

[blaze02]

HEy moses, did upping your nutes solve your problem??

Im having horrible issues transitioning from my veg tent (1000watts--, unsealed, coco pots floranova at 5ml/gal calplex at 3ml gal and dripclean at .5 ml, hand watering) to my sealed flower room (same 1000w hortis). I have sentinel burner and controller.

I never use to have problems but ive been going nuts over the last year trying to narrow down my problem. thought it was offgassing, low humidity from my a/c, even oxygen deficiency because it always happens within 24 hours when i move perfect plants in. Their ruined fast and get yellowy and stunted with purple stems that snap instead of bend when super cropping. I always have to wait a month constantly topping until they come back to acceptable form. Luckily i still get quality OG, but my turnover sucks! If you or anyone can help i would really appreciate it. i may start my own thread too. thanks!