First sealed grow room build out. Couple major questions regarding CO2 levels at night and controlling ppm during dark hours.

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Mcmc631

Mcmc631

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back ground info:
Room size: 10x20
Location: basement
Grow room: sealed
Medium: hydro
Method: RDWC
Plants: 10
CO2 tank: 20lb running at 1200 ppm flower
CO2 regulator and controller: yes
Lights: (4x) HLG 600RSpec
Air scrubber: yes
8000btu ac unit: yes
Dehumidifier: yes
Oscillating walll mounted fans: 4x yes
Ph controller: yes

Ok so at night I know I don’t have to run CO2 as the plants are naturally producing it during dark hours. I have read that this can cause CO2 levels to spike to 1500 ppm during dark hours. I have also read the only effective way to combat that this is to pump in fresh air at night.

Being that my room is meant to be sealed wouldn’t that defeat the purpose of a “sealed” grow room? Also isn’t that the point of the air scrubber so I don’t have to pump in fresh air? Thanks in advance, will post pictures when it’s all finished currently literally just got got cutting all boards to be be framed prior to insulating and applying vapor boards.to concrete walls
 
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Beowuuulf

Beowuuulf

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What's the problem? The spike to 1500? It will be fine. You can run 2000ppm+ co2. Don't inject co2 at night and don't worry about removing any co2 the plants make at night.
 
1diesel1

1diesel1

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Main purpose to seal a grow room is to control effectively your co2 level without loosing content. You need a titan co2 controller, it controls output with lights on and shuts it off with lights out.
I have used this controller effectively for years.
There is no need for fresh air intake during lights out. I have never had any issues.
Main thing is controlling your temperature when the lights are out and obviously when lights are on.
 
Mcmc631

Mcmc631

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Main purpose to seal a grow room is to control effectively your co2 level without loosing content. You need a titan co2 controller, it controls output with lights on and shuts it off with lights out.
I have used this controller effectively for years.
There is no need for fresh air intake during lights out. I have never had any issues.
Main thing is controlling your temperature when the lights are out and obviously when lights are on.
Sweet I have an autopilot controller that I’ll be using, there’s just so many mixed reviews on venting and not venting the grow rooom after lights out. I heard running a small slight stream of fresh air is also most beneficial.. calling it a hybrid sealed room? Defeats the purpose if you ask me. I just finished with my vapor barrier boards on wall one
 
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Fairytalez

Fairytalez

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Hey bud.. I got a sealed grow I'm almost done building myself. To answer your question.. firstly I would increase the CO2 to 1500. But to fix the spike problem.. all ya gotta do is stop feeding CO2 just 1 hour before lights off, and don't start feeding CO2 again until 1 hour AFTER lights come on. Boom.. that's how us sealed growers fix that problem without having to break our seal.
 
Fairytalez

Fairytalez

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Oh and also.. your choice in an Autopilot is better than a titan according to the reviews. I bought one myself. Can't wait to try it. It's supposed to be a TRUE set it and forget it style controller.
 
H

High95

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Are you up and running in your room yet? I run a similar setup, same number of lights, smaller space. Curious to see how your space is working out. I'm paused to do some upgrades and one of them is putting ventilation back in, the other is my second dehumidifier upgrade. I'm planning on venting during lights out at the very least, as my temps were staying same lights on and off due to dehu running full bore non-stop. I had a Frigidaire residential unit at first, which didn't stand a chance, upgraded to a commercial crawlspace dehumidifier, but as I got the hang of running them harder, it was obvious even that unit was woefully undersized and couldn't get the humidity to where I wanted it, luckily it heated the space up so much I was able to manage by running higher temps, but electricity prices have shot up where I am and after finishing the last run I went back to the drawing board looking to save on energy costs wherever I could. Venting at night, maybe even during the day by either running short bursts or coordinating with CO2 release. I'd be curious to compare how much your plants are drinking in RDWC vs my coco DTW setup. I'm not very active on this or any other forums, but I'll check back in to look for replies. Maybe we can bounce ideas around, cuz I know I'm looking to implement more low tech solutions(meaning cheaper) around maintaining my environment.
 
RootsRuler

RootsRuler

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OP.....I had just finished transferring 84 vegging plants into a 40 ft bloom room shipping container. I was pretty tired so I dragged in a 50 lb tank of CO2 and set up the controller and valve. Once I had it programmed I turned it on, shut the door and left. The next morning I went to check on the girls and noticed the CO2 PPM meter was at 390ppm! WTF? I checked the log and I noticed it got to almost 3000 ppm in the room! Oh Shit!

I checked the CO2 gear and noticed the pressure level meter had a crack in it and leaked all the CO2 into the room within a few hours. I was sure I killed the crop. Pulled some FAT colas out of that room.

Moral of the story? High CO2 isn't a bad thing. Don't sweat it. If they survived they will be fine.
 
Aqua Man

Aqua Man

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High o2 is more of a concern than high co2 from a plant perspective
 
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Se7en07_Exotics

Se7en07_Exotics

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I run a sealed flower room also and usually start my co2 around 1200 ppm's when I first flip to flower then increase to 1500 ppm's by the end of the week or during the second week of flower. As far as the Co2 spiking and needing to vent or add fresh air throughout the night if you have an exhaust fan then there is no need IMO. I know you said you have a scrubber in there, but does it exhaust or do you have an exhaust fan setup in the room? If not I would definitely think about adding one or instead of just scrubbing the air I would use that as an exhaust fan/scrubber instead. In my opinion the only reason you would need a scrubber is to help keep the smell down which I also use, but I use it along with having my exhaust fan hooked up inside the tent and I run the scrubber outside as an extra precaution. I personally use a Trolmaster Hydro-X which controls EVERYTHING, but basically I keep co2 on up until the lights kick off then after 30 mins of the lights being off I kick on my exhaust fan for 5 mins and then for 3-5 mins every hour or you could even do 5 mins every other hour if you wanted. This will not only suck out the co2 and humidity once the lights kick off so it doesn't spike, but it will help you maintain your target VPD and environment since it is sucking out the stale/humid air every hour or so. This has always worked great for me, just a suggestion though. Here is a pic of my flower room, it's a 10x10 fully sealed...
 
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