Sealed Room & CO2

[DRMedical420]

Hi All,

I need some advice.

I am currently building a sealed room, I have questions:

1. I will be using co2 introduced into the climate-controlled room, is there any reason I would want to exchange the air inside the room with fresh from outside during the day or night?
2. If I didn't exchange air with the outside world what would be the consequences?
3. What is the reason for adding co2 just before your light on cycle?
4. Is it important to maintain those levels throughout your light cycle or can you introduce co2 once and let the plants use it up throughout the light cycle?
5. Is it best practice to swap out the co2 enriched air in grow room with fresh air just before the dark cycle.

Looking forward to reading your response.

 

[Jackalope]

I don't have all the answers for you. I do have a one. If you are adding Co2 to a tent you don't want to exchange air. You would be wasting Co2 that way. As far as I know. Co2 is the only thing that needs to be replaced or enhanced when air is considered.

One thing to remember.Your plants are going to be in high gear and growing fast. If you run into problems they will be moving fast also. Keep a good eye on your plants for deficiencies.

 

[DRMedical420]

@Jackalope Thank you for the info, much appreciated.

 

[DRMedical420]

If I didn't exchange air with the outside world what would be the consequences?

This is the burning question!!!!!

 

[meffa]

From just the standpoint of will the plant care if there isn't an exchange, by itself that wouldn't bother the plant, however you'll likely need to vent and I'll tell you why - HUMIDITY!

I tried supplementing throughout the day without any venting and my tent was like a rain forest. What I ended up doing was supplementing for 45min and venting for 15 every hour. You can monkey around with that to see how far you want to stretch things. Co2 usage wasn't a concern as it reached the 1200ppm I centered at pretty quickly and the tent keeps it in pretty good. I also had my intake and exhaust running full-time at night, then back to the on/off with the Co2 during the day. I read that the plants do better when the Co2 drops down and spikes up, but who knows. I only have 1 grow under my belt but my stuff came out awesome! I spent a lot of time figuring this out and think this is the best approach.

My flower tent is a 4x8 and I have oscillating tower fans in each corner and 6" intake and exhaust fans. I'm 100% onboard with supplementing Co2, but I'm a firm believer in keeping the air moving and exchanging it out periodically.

 

[DRMedical420]

@meffa Thank you for your response.

I have complete control over humidity, temperature, co2 and even enrichment o2 to the roots in my high-pressure aeroponics tubs.

With enough capacity for dehumidification, I should never need to exchange fresh air.

 

[meffa]

@meffa Thank you for your response.

I have complete control over humidity, temperature, co2 and even enrichment o2 to the roots in my high-pressure aeroponics tubs.

With enough capacity for dehumidification, I should never need to exchange fresh air.

What are you using to dehumidify? I put a small dehumidifier in my tent and set it up to vent out, but it exhausted out the Co2. It got too hot if I didn't vent out of the tent.

 

[The Happy One]

Here's my spin on Co2. First, the entire idea behind adding Co2 is to provide the plant the ABILITY to utilize more light and convert it into energy. For instance in our atmosphere we have somewhere around 400 ppm Co2 in the air around us. At this ratio our plants have the ability to consume somewhere between 600 to 800 PAR. Folks may argue, but in my opinion anything OVER an 800 PAR with atmospheric levels around 400 ppm is peeing in the proverbial wind.
However, once you send the Co2 levels to around 1000-1100 ppm and bump the PAR up over your canopy to over 1000 PAR, your setting your plants up to thrive like they did when the dinosaurs were ruling the earth. Think of it like a supercharger for your plants. Now we got that out of the way, moving onto your questions.
1. Once again, it's my opinion you don't need to ventilate your room if it's truly sealed and you can reliably introduce additional Co2 into the room.
2. Consequences of NOT ventilating room? None, provided you can:
a. Maintain required levels of Co2
b. Maintain humidity levels. Keep in mind when running elevated Co2 in hydro, plants can drink a LOT of water. 85 to 90% of what they drink is tossed into the room through the leaves in the form of humidity. This can mean having to remove a LOT of water every 24 hrs. 132 females in full flower under 1100 ppm Co2 maintaining 50-60% rh can put 350 to 500 pints of water in that room in a 24 hr period. That's a LOT of dehumidification.
3. The reason for adding Co2 only during lights on is due to the plants basically "sleeping" and not using much Co2 during lights off.
4. Is it important to maintain levels during lights on? Yes. A Co2 controller with a light sensor takes care of those duties, and will regulate those predetermined Co2 levels, shut off during lights off and back on the moment light come back on.
5. We never exchange the air in a sealed grow room. As long as we maintain Co2 levels, we're good to go.

Good Luck!