to seal or not to seal

trying to figure out the air replenishment side of my room and feel like I am at a crossroads with each path having a similar price.

room is 13.5x19x9
24,000 btu window unit
110btu furnace heating grow room, garage, and adjacent room
2x3 seedling tent with 100 watt led
5 4x4 tents with 650 watt led
1 3x3 dry tent
each tent will be on a controller to dial in environments as needed

original plan was just to vent each tent outside and call it a day. Then i started thinking about depleting the oxygen in the room so started thinking 12 inch intake filter/fan and 12 inch exhaust filter/fan. Once i started pricing it out, i realized I could run a 4 or 8 burner NG co2 generator and controller for the same amount if not less. I already have the gas line in the room and would just maintain a normal 500ppm range.

Keeps the room enclosed and no exterior signs of the room, helps control odor, and theoretically should make the environmental units job easier.

reason for individual tents is ability to run different strains and keep a constant harvest coming in. also lowers risk of crop loss due to pest infestation in case it happens. also plan on running larger plants so moving them from a veg room to flower room in soil was going to be a pain. also easier to start the project and build on as funds become available for the multiple tents, lights etc. I did catch a break for ordering 4 lights at once though so that happened lol


so after this longwinded justification for my room design, what are your thoughts on sealing it and running a low amount of co2 or doing the traditional intake and exhaust fans?

After some time, I am leaning towards keeping it seeled with a co2 generator to keep normal co2 levels, with an exhaust fan to pull air a few times a day. Any reason I shouldnt go this route?

I am reading a 5-10 minutes every 4 hours at night and maybe 2 times during the day for the fan to pull out. Looking at burner descriptions for my room size it is recommending an 8 burner but if am just looking to maintain normal co2 levels would the 4 burner cut it? not a huge price difference but not planning on pushing high co2 levels

anybody on here doing anything similar? Any of the co2 guys have any input? Electrical is getting finished this weekend so i want to get stuff ordered but hoping to hear from a few experts

Xsan said:

anybody on here doing anything similar? Any of the co2 guys have any input? Electrical is getting finished this weekend so i want to get stuff ordered but hoping to hear from a few experts

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All depends how much experience do you have and have you ran a closed room with co2 before

done a few rounds, not a ton of experience but figure I will gain it quickly with this setup. Never done a closed room with co2. Was hoping if the idea was just to create an enclosed environment it would be as much of dance as changing co2 ppm levels frequently, just one controller to maintain normal levels so to speak.

Xsan said:

done a few rounds, not a ton of experience but figure I will gain it quickly with this setup. Never done a closed room with co2. Was hoping if the idea was just to create an enclosed environment it would be as much of dance as changing co2 ppm levels frequently, just one controller to maintain normal levels so to speak.

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OK sweet as long as you're environment is on point AC and humidity you're co2 will work out I'm running one now and I love it closed room for me all the way I prefer it my yield is incredible with rockwool ,co2 , I run in veg 650ppm flower 700 to 1000 ppm depending on the strains really

hvac guy was just here to see what he was looking at for the furnace replacement, he is going to t off a gas line for me to do the generator. still open to fans if someone has a big reason not to do semi sealed

@bk78 @xox @Herb & Suds Which direction would you folks head at this point. I just looked at the mr cool mini splits and that will have to be an upgrade down way down the road. I am seeing three options at this point.

1. seal it and add co2 at a regular atmoshperic ppm. more sterile room than co2 boosted room idea.
2. two 6 in passive intakes and 2 6 inch exhaust set to run for 5 minutes every hour or?
3. just the 2 6 inch exhaust and pull fresh air from door jams and such
4. open to other ideas.

I run a 20x30 with a 3 ton mini split, HLG lighting, Spartan controller, Ares 8 burner on propane, and sealed. No air coming in or going out. Works great. Veg on the gas at around 650-850, flower- 1000-1400ppm. No problems. You'll find that at those levels, they can take more heat, light, and nutes than without CO2 enrichment... and don't worry about working in the high CO2. Natural air is about 400ppm, a closed classroom full of kids- 3000-4000ppm, a submarine 8000-9000ppm. We breathe out 30-50,000ppm every time we exhale. When we have 4 people working in the room, the CO2 generator will not kick in because we are bringing the ppm up to 1800-2000 ppm just by being in there.

DoubleAtotheRON said:

I run a 20x30 with a 3 ton mini split, HLG lighting, Spartan controller, Ares 8 burner on propane, and sealed. No air coming in or going out. Works great. Veg on the gas at around 650-850, flower- 1000-1400ppm. No problems. You'll find that at those levels, they can take more heat, light, and nutes than without CO2 enrichment... and don't worry about working in the high CO2. Natural air is about 400ppm, a closed classroom full of kids- 3000-4000ppm, a submarine 8000-9000ppm. We breathe out 30-50,000ppm every time we exhale. When we have 4 people working in the room, the CO2 generator will not kick in because we are bringing the ppm up to 1800-2000 ppm just by being in there.

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Thank you for the input. With that being the case, if I am going to be going in and out daily to check plants, train, add water to humidifiers, trim, etc. do you think I could run with out the burner? I am not sure how I would dial levels in for each tent so I am just concerned about the stale air/lack of o2 facor but am thinking with only 5 plants and me going in and out I might be able to just keep it sealed and not be as concerned with odor. I am legal but not looking to advertise to the town lol

Xsan said:

Thank you for the input. With that being the case, if I am going to be going in and out daily to check plants, train, add water to humidifiers, trim, etc. do you think I could run with out the burner? I am not sure how I would dial levels in for each tent so I am just concerned about the stale air/lack of o2 facor but am thinking with only 5 plants and me going in and out I might be able to just keep it sealed and not be as concerned with odor. I am legal but not looking to advertise to the town lol

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If you're going sealed, you will need a burner. I've "experimented" by leaving mine off to see rate of absorption, and they sucked the CO2 down into the low 200's pretty quick. So are you going to be be running a couple of tents in veg, and a couple of tents in flower in the same room?... or all vegging and all flowering?

a couple in veg and a couple in flower. just going to continuously cycle a single plant/tent every 5 weeks. different genetics in each tent also. If I go sealed and run the burner with plants in both stages would i just run it at 500 or so?

btw, was checking out your setup...very nice and impressive! i only got to the first bit but totally agree with playing nice with the law

I would think that a happy medium would be around 800ppm CO2 for both veg and flower. Just make sure you don't have any light leaks from your veg tents to your flower tents.

DoubleAtotheRON said:

I would think that a happy medium would be around 800ppm for both veg and flower. Just make sure you don't have any light leaks from your veg tents to your flower tents.

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Thank you! It is such a relief to get some input from one of the vets on here. My apologies for not tagging you in my initial post. I am still new and haven't tracked all of you yet. Plus it seems more and more of you are leaving. I was bummed to see @Renfro go.

If I am just going for 800, would you think 4 or 8 burner?

also, sorry to be a pest but I had one more thought. I have read about dropping co2 to 0ppm for last few weeks of flower. guy at lgs said it was a taste thing. what are your thoughts on this?

Xsan said:

Thank you! It is such a relief to get some input from one of the vets on here. My apologies for not tagging you in my initial post. I am still new and haven't tracked all of you yet. Plus it seems more and more of you are leaving. I was bummed to see renfro go.

If I am just going for 800, would you think 4 or 8 burner?

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renfro i wish him well.. he said he would still join us now and then

Billytheluther said:

renfro i wish him well.. he said he would still join us now and then

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tagged him just in case lol

Does oxygen matter in a sealed room at all? Or just the co2

Xsan said:

Thank you! It is such a relief to get some input from one of the vets on here. My apologies for not tagging you in my initial post. I am still new and haven't tracked all of you yet. Plus it seems more and more of you are leaving. I was bummed to see @Renfro go.

If I am just going for 800, would you think 4 or 8 burner?

also, sorry to be a pest but I had one more thought. I have read about dropping co2 to 0ppm for last few weeks of flower. guy at lgs said it was a taste thing. what are your thoughts on this?

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There’s not much price difference between the 2. I’d do an 8.. it’ll burn shorter cycles, and you’ll have a 4 burner burn longer per cycle, so, they’re gonna use the same amount of NG.
I just start dropping the Ppm at the ripening stage, but alway keep it at least at 500 till the chop.