CO2 injection in a 5 x 5 tent

RootsRuler · Jul 14, 2022

Gurus? Please school me on how CO2 works to improve growth rates. I know that it improves photosynthesis and allows for higher grow temps but I'm more interested in its application.

Do you have to maintain a high PPM rate in the atmoshphere to be able to take advantage of CO2's benefits or can you spray them with CO2 and, since it's heavier than air it will lay on the leaves or does it draw it out of the atmosphere as it photosynthesises?

Kodesh · Jul 16, 2022

The upshot of increased CO2 is it raises the ceiling on how much light the plant can utilize for photosynthesis. Any increase over baseline will be beneficial and 1500ppm is the sweet spot where increasing it more won't give much benefit. No CO2 for lights out so it's not wasted, can either get a controller so it stays where you want or just put the tank/regulator on a timer. You do wanna put the tube up above your plants so it drops right on them as CO2 does sink, but it will fill up the room if it's sealed decently and can't leak out too quickly. And yea, the plants absorb CO2 through their leaves so eventually they use it up if the air isn't being exchanged or enriched.

Here's a calculator for setting up a timer:
https://www.titancontrols.net/tools/co2-flow-calculator

tobh · Jul 16, 2022

I wouldn't do CO2 injection in a tent, especially if the tent shares a space that is also utilized by humans for extended periods of time. 1500ppm is the sweet spot as @Kodesh said but that's also at danger to life and health levels for humans. You simply cannot seal a tent well enough to make using CO2 economical imo.

Now, with CO2 you're able to run higher par levels, and you can also push the plants harder with nutrients which in turn boosts yields.

The last I can add here is CO2 shouldn't be entertained until every other detail of your setup is dialed in -- if you aren't at the absolute limit of what your setup is capable of producing, you don't need CO2 yet.

Consider it like the cherry on top of an ice cream sunday -- not terribly necessary, but sure is nice to have that just makes the rest of the ensemble that little bit better.

Kodesh · Jul 16, 2022

Tobh made some really good points if your tents are in your living space you may also already be up around 1000ppm just from you/family/pets breathing and the air not fully exchanging.

RootsRuler · Jul 16, 2022

tobh said:
I wouldn't do CO2 injection in a tent, especially if the tent shares a space that is also utilized by humans for extended periods of time. 1500ppm is the sweet spot as @Kodesh said but that's also at danger to life and health levels for humans. You simply cannot seal a tent well enough to make using CO2 economical imo.

Now, with CO2 you're able to run higher par levels, and you can also push the plants harder with nutrients which in turn boosts yields.

The last I can add here is CO2 shouldn't be entertained until every other detail of your setup is dialed in -- if you aren't at the absolute limit of what your setup is capable of producing, you don't need CO2 yet.

Consider it like the cherry on top of an ice cream sunday -- not terribly necessary, but sure is nice to have that just makes the rest of the ensemble that little bit better.

Kodesh - Great point about already present CO2. Gonna see if I can measure the CO2 presently in the lung room.

Tobh - I've already pretty much dialed everything else in and was looking for other ways to push the girls. I've run CO2 injection in larger grows like 40ft containers or 20 - 30 light large sealed rooms but I wasn't sure if the CO2 was pulled by the plants from the air or if the CO2 falls onto the leaves and the plants utilize it from there. I assume it pulls from the air since PPM needs to be maintained but was hoping maybe it was application driven because I had the same safety concerns Kobesh did.

Another reason I was inquiring about CO2 in the tent was because I was thinking of running a dry ice cold box to help drop temperature in the tent as the dry ice is going to introduce CO2 into the tent.

My current setup includes a 5 x 5 tent equipped with an AC Infinity 6" fan/Carbon Filter/Controller 67 for ventilation along with a 6" and 9" fan for air circulation inside the tent. Lighting is a Bestva 2000w LED light. I'll be growing 6 plants in a SCROG and will be adding another 2000w LED light as the scrog will be wall to wall so I'm going to need to be able to cover the entire interior canopy. Adding another light is going to increase the temperature in the tent.

So far the Vent system has been able to keep the temp and humidity within parameter but with the addition of the extra light I'm not sure it's going to be able to keep up. The lung room is kept at 74*. First light raised the temp in the tent to 77*. I assume adding another will raise it another 3* but I seem to remember some sort of formula that says when you add heat sources to an enclosed environment it goes up exponentially not linearly so I'll have to see what the increase will be.

tobh · Jul 16, 2022

RootsRuler said:
Kodesh - Great point about already present CO2. Gonna see if I can measure the CO2 presently in the lung room.

Tobh - I've already pretty much dialed everything else in and was looking for other ways to push the girls. I've run CO2 injection in larger grows like 40ft containers or 20 - 30 light large sealed rooms but I wasn't sure if the CO2 was pulled by the plants from the air or if the CO2 falls onto the leaves and the plants utilize it from there. I assume it pulls from the air since PPM needs to be maintained but was hoping maybe it was application driven because I had the same safety concerns Kobesh did.

Another reason I was inquiring about CO2 in the tent was because I was thinking of running a dry ice cold box to help drop temperature in the tent as the dry ice is going to introduce CO2 into the tent.

My current setup includes a 5 x 5 tent equipped with an AC Infinity 6" fan/Carbon Filter/Controller 67 for ventilation along with a 6" and 9" fan for air circulation inside the tent. Lighting is a Bestva 2000w LED light. I'll be growing 6 plants in a SCROG and will be adding another 2000w LED light as the scrog will be wall to wall so I'm going to need to be able to cover the entire interior canopy. Adding another light is going to increase the temperature in the tent.

So far the Vent system has been able to keep the temp and humidity within parameter but with the addition of the extra light I'm not sure it's going to be able to keep up. The lung room is kept at 74*. First light raised the temp in the tent to 77*. I assume adding another will raise it another 3* but I seem to remember some sort of formula that says when you add heat sources to an enclosed environment it goes up exponentially not linearly so I'll have to see what the increase will be.

ah ok. given the internet and all being strangers, i approached with a response for someone not familiar with the intricacies of running CO2. So, you're running the tent vented into a lung room, which I'm assuming is not inhabited for any measurable amount of time by humans.

Will you have a way to purge the CO2 before you enter the room for maintenance?

Aside from that, you're correct. Adding additional lighting/heat sources increase temps exponentially. With LEDs, you should be running at 80F anyways imo. Since they don't generate the same kind of infrared that HID does, they don't warm the leaf surface the same as older technology did, so warmer temps are required. However, anything over 82F in a fully dialed setup warrants CO2.

What setup are you thinking for CO2? Tanks or a burner?

Full disclosure, I've not run CO2 yet, but I've drooled (and read) plenty. @Aquaman can provide much better input that I, he may be around later tonight or tomorrow. All that being said, sounds like you're ready for CO2. Without CO2, you'll run into calcium uptake issues with the higher light availability and if the heat gets out of control, transpiration is going to completely stop and you'll end up in a worse situation.

EDIT: this is a note based on my own understanding, but basically what CO2 does it it increases the air density which forces the stomata to stay open in more volatile environments, which subsequently increases transpiration cascading down to higher water and nutrient uptake. This all leads to faster plant growth and higher yields. Hence needing higher temps, more light, more everything to gain the benefits of the gas.

CO2 injection in a 5 x 5 tent

CO2 injection in a 5 x 5 tent

RootsRuler

Kodesh

tobh

Kodesh

RootsRuler

tobh

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