Is there any need to purge CO2 in a sealed room?

[the_extremist]

I just set up my sealed bloom room and I'm using tanked CO2 with a Sentinel Regulator and CPPM-4 Controller. Pretty slick set up. Set point at 1500ppm.

When I bought all this stuff at the hydro store the guy told me I need to purge the CO2 in the room daily during the dark period. He said this was because the plants need more oxygen at night and after a few days the plants will become unhappy and start eating lower leaves for some reason.

My inner skeptic says this is horse shit for two reasons. A: because I haven't read about purging CO2 being necessary anywhere here on IC and B: because if I purge my CO2 daily I'll be back at the hydro shop buying a refill much more often. Seems like a good motivator for the salesman to tell me not purging will hurt my plants.

Is this necessary? Is the guy at the hydro shop full of shit? I've run the room at 1500ppm without purging for five days now and the plants look fine. Growing like crazy actually.

 

[Phillthy]

i have never had to do this. i wouldnt bother purging. there are no adverse effects.

 

[B. Friendly]

the plants are going to soak up all the co2 they can get.
zero need to purge your girls will do it for you.
plus why ya ever thinking of getting rid of one of the most important fertilizers there is period.
shit man add co2 for better crop and yeild.

 

[the_extremist]

Right on, I thought so. I think the hydro guy just wants to sell me lots of CO2 refills.

 

[Marshall]

no need to purge.

But it wont change how much you buy. The co2 you added before lights went off, wont be there when you turn lights on. Leaks, plant usage, etc.

 

[odium33]

ya i have heard the same things. but personally I dont purge at all. our ppm in the morning is between 800-1000 usually and my plants turn out great!

 

[supermanlives]

during the dark period you shouldnt be running co2 . purge away at dark if you feel the need.ventillation at dark pariod prevents humidity buildup.if you got a dehuey than no need at all

 

[the_extremist]

The CO2 doesn't run during nighttime. The controller runs on a photocell.

I have a dehuey and my max RH never sees 60%. I must have done a really good job of sealing my room because at lights on my ppm's are around 1700-1800. I thought this was weird. So I checked the bottle and regulator, no leaks. Wtf? Then I read in another thread on CO2 where DHF explained that at night time the plants actually "shit out" what they don't use during lights on.

 

[Bud-Boy]

NO

 

[shuswap]

i am having adverese effects and i beleive its from high co2 levels at night,lights on co2 is set at 1200,lights out four hours after going dark the levels are at 1900,yep shes sealed tighter then a bulls ass in fly time,but i am getting lower leave damage,resembles magnesium diff,lowers go yellow,tips curl up and then brown off,slowly spreading to high leaves,im thinking either i add ozone at night with a controller to keep it around 0.1 ppm as safe with wcb regs or to vent periodically at night,any feed back guys?

 

[Holdin']

Re: Is there any need to purge CO2 in a sealed room?

The CO2 doesn't run during nighttime. The controller runs on a photocell.

I have a dehuey and my max RH never sees 60%. I must have done a really good job of sealing my room because at lights on my ppm's are around 1700-1800. I thought this was weird. So I checked the bottle and regulator, no leaks. Wtf? Then I read in another thread on CO2 where DHF explained that at night time the plants actually "shit out" what they don't use during lights on.

I've never heard of or seen this happen... my room is pretty tight, and with 1200ppm during the day, the ladies usually wake up to about 6-700ppm. Have you tried turning off the regulator before lights out to make sure your photocell is working properly? Although overshooting setpoint by 2-300ppm would be unexpected IMO.... that's pretty weird.

 

[bushdoctor215]

i am having adverese effects and i beleive its from high co2 levels at night,lights on co2 is set at 1200,lights out four hours after going dark the levels are at 1900,yep shes sealed tighter then a bulls ass in fly time,but i am getting lower leave damage,resembles magnesium diff,lowers go yellow,tips curl up and then brown off,slowly spreading to high leaves,im thinking either i add ozone at night with a controller to keep it around 0.1 ppm as safe with wcb regs or to vent periodically at night,any feed back guys?

Whats up shu! I ran into that problem back in the day and that plantbuilder dude recommended dark period exhaust. Worked like a charm. Now i`m thinking about flip flop rooms with a lung. excess co2 from the dark side could be used up by lit side in theory. btw, i`ve had better luck keeping my co2 levels around 1000ppm...

 

[shuswap]

bushy all good,no more ht bitches in the bars lol, yeah im gonna rig up an evening exhaust one room exchange an hour to start with,u check out them blumats yet?

 

[shuswap]

so your thinking that youll be able to run two rooms with no co2 supplementation besides what the night plants are perspiring,lol like a perpetual wheel

 

[bushdoctor215]

so your thinking that youll be able to run two rooms with no co2 supplementation besides what the night plants are perspiring,lol like a perpetual wheel

Naw... The lung room will be set at 1000ppm. Light room and dark room constantly dumping into lung. Any excess co2 produced in the dark room will be consumed by the light room meaning the controller won`t kick on until the lit plants consume the excess. I think it will work and no more dark exhausting. I`m a little chicken of the blumats with the runaway issue. I`ll give them a chance though, just on a couple plants...

 

[Azeotrope]

Ethylene gas can accumulate if you don't open the room or purge/vent it at some point. I run sealed with CO2 with no venting at all, but I open the door twice per day. IMHO CO2 is best at around 80f - 82f and about 900-1100ppm.

 

[icdog]

Try setting your regulator to turn off at an hour or more before lights turn off to allow the co2 to drop to a normal level and monitor the levels and see if it makes a diff.
Sounds like the levels are too high at lights off and go up during the nite or you have a leak somehow.

 

[youngtrader9689]

running at 80-82 have you seen less cyrstals? i just got done with my first vented room ever and noticed that the crystals were bigger and more abundant with the lower temps

 

[Azeotrope]

I will drop the temps a couple degrees each week. It is refrigerated, but in late veg and the first 3-4wks of flower, 80-82f.

 

[Granger2]

What icdog said... Good luck. -granger