Controlling co2 in a tent?

[NorCalFor20]

I have a Growlab 145L and its roughly 4x8 im gonna set up co2 in there, but I want to know how to keep from just exhausting it right out of the tent? any suggestions?

i am using a 8 inch can max fan to cool my 2 1000s and it shoots right outta the tent, i also have an 8inch max intake fan with a hepa filter on a speed controller and another 8inch max fan exhausting my carbon filter.

thanks

 

[PuReKnOwLeDgE]

only way to do it is to seal her up.

Seal everything very well, air cool your lights with air form outside the room with hepa filter atached and right out, no contact with air in room. Seal ducting very well.

Add a dehumidfier, add co2, shoot for 82-84F and if the tent can't handle that add an AC.

Set your carbon filter on the floor and attach a fan recirculating air inside the room.

 

[Lazyman]

AC is mandatory, no air exchange with CO2 is the goal. Never seen anyone do it successfully in a tent either, sorry bro.

 

[tuinman]

A friend attempted to do the same thing with the same tent - it's rather difficult to keep the tent sealed and cooled down without either:

A) Putting an AC in the tent (and losing floor space)
B) Using water heat exchangers on the hoods (expensive)

There was an 8" exhaust hooked up to the controller that would clear the tent out when temps crawled too high - it went off often enough it turned out to be easier to seal the entire room let the tent exhaust as needed.

Edit: This was using a tank & controller.

 

[bobjoe 69]

It is just to hot for a tent I have a home box 4x8x8 and you could burn for 30 seconds and then you had to stop it the temperature was just to much and to danger of fire out weighted Any Benefits

 

[Lazyman]

CO2 generators should never be used in a tent, tanks only. Tanks are the better way to go for grows under 10X10 feet anyway. Over that and you can have some debate.

 

[Philosophelon]

Note: For the following post, except for my final suggestion, I am assuming that you need to use an A/C anyway, because you are limited by the outdoor air temp/rh where you grow, AND/OR you have limited space and want to maximize your yield for a given space. If you live somewhere with access to sufficiently cool/dry outdoor air and you have space for more lights/plants, you can skip to the last paragraph.

AC is mandatory, no air exchange with CO2 is the goal.

I completely agree with Lazyman, you're going to have to either:

A) Seal the tent.
B) Seal the room the tent is in.
C) Seal the tent and use a separate (sealed) lung room.

If you have enough space in your tent, the easiest thing to do is to put your CO2 tank, dehuey, and A/C in the tent; then seal the tent. Note that I've never attempted to seal a tent, so I don't know how well-sealed you can make it.

If you don't have enough space in your tent, you'll need a lung room -- but if you're going to build a sealed room to use as a lung room, you might as well just use that room for your grow. Since I assume you don't want to build a sealed room, I have two suggestions for you.

1) Seal the room that your tent is in, and use that as a lung room. Put your CO2 tank, dehuey, and A/C in the room your tent is in. Then intake cool/dry/enriched air from the room into the tent, and exhaust hot/wet/depleted air from the tent back into the room. But depending on the size of the room your tent is in, that might be pretty inefficient for a single tent. However, that is probably easier and more efficient than using two tents (one lung tent and one grow tent, see suggestion #2), because it seems like it would be hard to seal a tent, although again, I've never tried. I have used a sealed room as a lung room with multiple tents inside said room, and it worked well.

2) Perhaps you could buy another tent and use the 2nd tent as a makeshift lung room. Put your CO2 tank, dehuey, and A/C in the lung tent. Then pull cool/dry/enriched air from the lung tent into the grow tent, and exhaust hot/wet/depleted air from the grow tent back into the lung tent. That way you still have a sealed system, although I don't know how well-sealed you could get the tents.

Note that I've never actually used a lung tent, but I have used lung rooms to cool/enrich more than one room with the same CO2 genny, A/C, and dehueys, and it works great. In fact, if I'm running (or building for a friend) more than one flowering room, I always do that to save labor, space, and money.

Can anyone with relevant experience chime in on the viability of and/or suggestions for sealing tents?

Finally, I have one more suggestion, in the event that you are not limited by space or the outdoor temp/rh. Don't use supplemental CO2. Instead of using extra electricity for an A/C and dehuey, run more light. You'll get more of an increase in yield from an increase in light than you will from supplemental CO2.

Sorry for the long post, hopefully it was helpful .

 

[tuinman]

I can at least say on the subject of sealing growtents, they're really not difficult to do so. Almost all have velcro flaps to seal passive vent screens, ect.

Great breakdown post.

 

[BlindDate]

Ya know, If you just get a little bigger tent your yield will be the same without the CO2 and it's associated problems.

 

[303hydro]

There are controls that sense temp humidity and ppm that will turn on your exhaust fan whenever temp or humidity gets too high ( you can adjust specifics ) and let your CO2 pump up too and maintain desired levels otherwise. Most also have a little photo cell as well so you never burn gas when the lights are off. You will waste a little bit of gas but it will work I've done it.

 

[Natagonnaworrie]

I have the exact same set up.. tent, lights, and fans, all though my fans are 6". Carbon filter IN THE AIR, high in the tent. CO2 is heavy. I have a CHHC-1 controller and 2 20# tanks. Each one lasts a week with 6" fan for the carbon filter set to 25% via a speed controller. PPM at 1500 weeks 1-4, then 1600 thereafter. I have AC cooling he lung room so that the canopy temps in the tent are 82 - 85 degrees. Carbon filter vents out the window, the other 1 6" fan vents the 2 1000w out the window. Cool air draws through the hoods making it not TOO hard to cool the lights.

Passive intake, just enough to keep the carbon filter from imploding the tent.

Also, by week 6 the carbon filter is creeping up on fan speed via speedster controller (for smell reasons). By then you are blasting through tanks every 3-4 days. It is very much a hassle and becomes expensive. Honestly, i have been debating not using gas.

 

[tuinman]

Carbon filter IN THE AIR, high in the tent. CO2 is heavy. I have a CHHC-1 controller and 2 20# tanks. Each one lasts a week with 6" fan for the carbon filter set to 25% via a speed controller.

Out of curiosity why is the scrubber inside your tent? In another small Co2 space I helped set up the scrubber is outside the grow area and is only turned on when it needs to be accessed - so 20 minutes before opening it, the scrubber is turned on full blast, remains that way while the room is unsealed, then left on for about 30-45 minutes after the room is resealed.

It's about the same size as your tent, and it takes two weeks or so for a 20# tank to run out at 1500ppm.

 

[ShroomDr]

I have tried this and ran into all kinds of problems. im in a 5'X10' tent.

First i tried to seal the air cooling system. Basically pull air to cool the light fixures from outside the tent. This basically seals the grow area, but causes the rH to soar.

Then i tried to add a dehuey inside the tent. This solved the rH problem, but this added too much heat (~91F).

So... when i get around to it, i think im going back to the sealed lighting system, and adding a separate exhaust fan for the grow environment.

Depending on how often i will have to run this fan to keep the tent's rH in check, will dictate if CO2 is feasible/worth the investment. Not sure where the cut off will be, but if the exhaust fan has to run more than 1/4 of the time (read: 15min on /45 off), its probably not going to be worth the CO supplementation. Not sure.

And FWIW, every time i see someone say CO2 is heavy i want to puke. CO2 is not that much heavier than the other gases we breath. If you have circulation fans, its going to get all mixed up, not pool at the bottom of a grow area, like people insinuate when they say 'CO2 is heavy'. We are not talking about Sulfur hexafluoride or Radon.

 

[tuinman]

I have tried this and ran into all kinds of problems. im in a 5'X10' tent.

First i tried to seal the air cooling system. Basically pull air to cool the light fixures from outside the tent. This basically seals the grow area, but causes the rH to soar.

Then i tried to add a dehuey inside the tent. This solved the rH problem, but this added too much heat (~91F).

So... when i get around to it, i think im going back to the sealed lighting system, and adding a separate exhaust fan for the grow environment.

This is the problem we had using the same tent size, eventually ended up just letting the exhaust fan run as necessary and sealed the room, which was cooled by an AC.

 

[ShroomDr]

My flowering tent is in the same room as my veg space, so pulling CO2 out of the tent will at least not be a total waste.

The room is cooled by an AC, and I still couldnt get the 'sealed light fixtures + dehuey' below 90F ([2] 600HPS).

Sealing the tent is not hard, but sealing the tent properly is. I dont want to cut a big hole in my tent to stick a combo AC/dehuey window unit in there, but maybe this is the best bet.

 

[tuinman]

My flowering tent is in the same room as my veg space, so pulling CO2 out of the tent will at least not be a total waste.

The room is cooled by an AC, and I still couldnt get the 'sealed light fixtures + dehuey' below 90F ([2] 600HPS).

Sealing the tent is not hard, but sealing the tent properly is. I dont want to cut a big hole in my tent to stick a combo AC/dehuey window unit in there, but maybe this is the best bet.

You could also try ducting the AC output directly into the tent. The reason we didn't go this route was:

A) The temperature controller was built into the AC control panel, no easy way to run it into the tent, so,
B) We'd have to figure out the best timing setting to kick the AC on, let it cool the tent, so,
C) The rest of the room the tent was in wasn't cooling down.

A couple things that helped when messing about with this idea was aggressive pruning - as the fans would reach maturity they'd (bit by bit) be stripped out, which cut down on transpiration and kept rH down. Unfortunately it's rather intensive to stop by often enough to do this since it's an ongoing process, and 'defoliation' as mentioned elsewhere isn't something I'm convinced about (although it'd be easier).

The other method that helped and is currently being used was blumat autowatering, it cut down general rH in the tent enough that the small dehuey sitting in there does not come on very often.

 

[peeranoia]

My buddy has 2 tents with c02, he aircools the lights and vents them into the attic.. the bedroom the tents are in is all sealed up and has c02 and a 1 ton portable AC to control the temp inside room..the tents just intake from the climate controlled room they are in.