Co2 in grow tent

I run a sealed room but I’m helping a friend setup a grow and he’s bought a grow tent. How do you use co2 in a tent if you have fresh air coming in?

You don't.
You might add supplemental but difficult to raise it to a certain percent constantly. Or put tent in sealed room

Step 1: Install a mini split air handling unit inside the tent. Or, cut a big enough opening in one of the walls, and push the whole tent up against a window already fit with an AC unit hanging from it, right where you made the opening, and tape it all up.

A few other options; stuff an inefficient portable AC in the tent with the hoses running out of the ventilation ports to the windows, or hookup a chiller to an external reservoir and pump liquid water/coolant from that res into a radiator & fan unit hanging inside the tent.
Keep it all sealed up.



Step 2: Hang a small propane or natural gas c02 generator\burner inside tent, or hookup bottles to a regulator and run the lines in. Plug into a co2 controller or program your timer, and let it rip. Use way less c02 in the smaller tent space than if you were gassing the whole lung room out.

Drop That Sound said:

Step 1: Install a mini split air handling unit inside the tent. Or, cut a big enough opening in one of the walls, and push the whole tent up against a window already fit with an AC unit hanging from it, right where you made the opening, and tape it all up.

A few other options; stuff an inefficient portable AC in the tent with the hoses running out of the ventilation ports to the windows, or hookup a chiller to an external reservoir and pump liquid water/coolant from that res into a radiator & fan unit hanging inside the tent.
Keep it all sealed up.



Step 2: Hang a small propane or natural gas c02 generator\burner inside tent, or hookup bottles to a regulator and run the lines in. Plug into a co2 controller or program your timer, and let it rip. Use way less c02 in the smaller tent space than if you were gassing the whole lung room out.

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no

You don't put anything inside the tent.You run the tent in a sealed room, sealed meaning it's not activly vented. The room your tent is in is called the breather room. You vent the tent into the breather room to exchange air. The breather room you climate control with a window ac, portable ac, or mini split. Also in then breather room you add the co2, from a burner or tanks.

nxsov180db said:

You don't put anything inside the tent.You run the tent in a sealed room, sealed meaning it's not activly vented. The room your tent is in is called the breather room. You vent the tent into the breather room to exchange air. The breather room you climate control with a window ac, portable ac, or mini split. Also in then breather room you add the co2, from a burner or tanks.

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lol what do you need the tent for then

xox said:

lol what do you need the tent for then

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To control smell, create a 12 hour dark cycle, ect.. I mean I guess you could put all that crap in a tent, but what size tent we talking? If you're gonna seal a tent and not vent it it'll need a/c and a dehumidifier and a co2 tank, so I guess you could put all that in 1 half of a 10x10 and grow in the other half, seems dumb tho..

If they’re growing for personal use in their home ambient co2 is plenty, no need to seal anything. Humidifier with hose set outside the tent for veg, exhaust fan set low, good sized dehumidifier in the tent’s room exhaust fan set to high in flower

You could hook up another smaller tent and put most the bulky equipment in that one, and connect both tents together with ducting so it actively recirculates through both of them. If you insulate the tents better you'll be saving on electricity as well as the c02 by having a smaller space.

Suppose there are pro's and cons to doing it either way. I did forget to mention its probably not worth it though, lol.

Greengrouch said:

If they’re growing for personal use in their home ambient co2 is plenty, no need to seal anything. Humidifier with hose set outside the tent for veg, exhaust fan set low, good sized dehumidifier in the tent’s room exhaust fan set to high in flower

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disagree, i have a co2 enriched room in my home and it is probably one of the coolest things ive built in this house

xox said:

disagree, i have a co2 enriched room in my home and it is probably one of the coolest things ive built in this house

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I’m sure it’s cool as hell, hardly a necessity though.

I'd like to run CO2 in my 2' x 4' tent and have run some numbers through chatGPT. The key obstacles to success are the need to control RH and temperature. These are major factors for growers who aren't in the frost belt. If you can grow in a basement, that will make a significant difference because of the cost of cooling may be significantly reduced.

According the chatGPT, the increase in yield from CO2 would be reduced because of the fluctuating CO2 levels that were caused by the need to frequently vent the tent to keep RH and temperature in check, with temperature being the main culprit. The changing amounts of CO2 will result in only 5-10% increase in yield.

Another approach is to create a closed loop system using the AC Infinity Terraformer in A/C mode to maintain temperature. That's $600 additional in hardware and that might also require the use/purchase of a dehumidifier. AC Infinity has a dehumidifier coming out later this year and it will run $150± for their mid-range model.

The increased upfront hardware cost (fixed) can be amortized over a few years but the killer is the price of electricity here in Southern California which I costed at $0.45 per KwH. The closed loop system uses far less CO2 and will provide the typical 30%± increase in yield but, for a home grower, that doesn't make up for the increased cost of cooling and drying the air.

I found chatGPT to be very helpful. It allowed me to model this issue using natural language and I was able to include any of the fixed or variable costs that I could think of. Once I had those parameters down, I asked it to amortize my costs over four grows and I got answers in a few seconds.

If you decide to use chatGPT or any AI source, make sure you check its work. In this case, chatGPT added the cost of electricity for the AC unit to the vented system, even though the AC unit was only used in the closed loop system.

These factors make running CO2 in a tent more cost effective:

• reduced need to maintain temperature and humidity-growing in a basement in the frost belt
• reduced cost to maintain temperature and humidity-located in a state where electricity isn't absurdly high
• cost of hardware not an issue-$600 for the Terraformer and $150 for the dehu
• can amortize cost of hardware-I'll be 69 years old soon and probably won't be growing much longer. OTOH, if you're a "youngster" you can amortize the hardware cost over two or three grows a year for X years
• grow in a larger tent-I ran the numbers for a 2' x 4' tent. The numbers for a 4' x 4' or a 5' x 5 would be far more attractive
• cannabis is a revenue source-very quick payback for the closed loop system because of the ~30% increase in yield.

Oh, if you're going to run CO2, you'll want to grow at 1200µmol. If you are taking cost into account, the payback period on a high output light could be as short as two grows, but I that's a rough guess. chatGPT can help you figure it out, though.

PS-I'm marking time until my next grow. We're just starting the summer temps here - 82, 83, 81 for July, August, September but then 76 and 69 in October and November - so I' be "fucking of local area" for another couple of months, at the very least.