Anyone running a sealed room without co2?

[Guest 18340]

Anyone running a sealed room without co2 supplementation? Curious as to results, bud quality etc.
Is it absolutely necessary?

 

[stink.whistler]

Without CO2 input to a truly sealed room, you will suffocate your plants.

 

[Guest 18340]

Yeah, i get that. But realistically most of us go in/out of our grow rooms several times a day, every time that door opens...
Just curious is all.

 

[Phillthy]

I have run a completely sealed room for months with no CO2. Just walk in and out a few times a day and you will be fine. I never had plants suffer. I did run AC and fans for recirc.

 

[inreplyavalon]

Doesn't an AC cool air from outside? While exhausting the warm air from inside? Then CO2 would be entering from the outside i think. sadly i don't know exactly how an AC works...

Most everyone stresses the importance of air exchange, for temp/humid control, and CO2 intake. I am surprised people have grown in 'sealed rooms' with no AC and had good results. Interesting. Thanks for sharing folks

 

[manwithnoname]

it depends if the a/c is set to recirculate

 

[Phillthy]

My AC recirculates. It does not take in air from outside (mini-split). My CO2 burner is on the way though

 

[yamaha_1fan]

I ran a sealed room for over a year, with a wall unit a/c recirculating, and no Co2. Plants were fine. But the Co2 did help alot with weight. I recently turned off the CO2 because of heat and noticed a loss in yield. It has been turned back on

 

[Philosophelon]

I actually just did an experiment with this (not entirely on purpose). I set up a new room a few months ago, my old co2 tank was fucked, and I had little room (electric-wise) for A/C & dehuey, so I couldn't use NG. So I decided, hey, I'll see what happens with no supplemental CO2.

I run a staggered harvest, so initially the room was not full, and I didn't have drippers set up for the first couple weeks, so I spent more time in the room. I didn't notice any problems until the room started to fill up with plants. I started getting weird leaf deformations and chlorosis on the new buds and budleaves.

So I hooked the cool tube hvac circuit intake up to the carbon filter (heretofore simply recirculating), ventilated the room, and the problem went away within about a day.

Here is my working hypothesis:

It may or may not be neccesary. I think it depends on the amount of leaf surface area and the volume of air in the room. If your plants use up the co2 too quickly before lights out, then they'll begin to suffocate. If not, you're OK.

Also, I would assume that just as increasing atmospheric CO2 concentrations increases the plants metabolic rate, decreasing atmospheric CO2 would decrease the plants metabolic rate, thus offering something of a 'buffer' by using less CO2 as the plants metabolic rate drops. Kinda like how our bodies use less food if we starve them.

 

[Phillthy]

It may or may not be neccesary. I think it depends on the amount of leaf surface area and the volume of air in the room. If your plants use up the co2 too quickly before lights out, then they'll begin to suffocate. If not, you're OK.

This makes complete sense. Well said.

 

[Guest 18340]

Hey Philosophelon, how big was the room and how many plants where in it when things started to get weird?

 

[sparkjumper]

My vegroom doesnt have co2 supplementation or fresh air intake and my plants veg great.I bought a 10 pak of RAE systems inc co2 tester cartridges just to check throughout the day and it never fell below 500PPM even with the largest vegging plants,usually about 20 or so.The co2 level inside a bldg is normally a bit higher than outside.I run an AC but thats about it and theres no fresh air intake.If you ever have any questions is easy enough to find out for yourself at about 5 bucks a pop

 

[mpd]

Mine is sealed with no CO2 because pests are just to pesky for me to tolerate in the grow room. No bugs, no problems and I've never (knock on wood) had a case of bud rot. Had a spider mite infestation once.

To make my grow program work for me, i put in a raised floor in the grow room (a converted half-bath) with a central open-site drain. I then sealed every joint in the room with silicone caulk (outlets, pipes, walls, ceiling and floors) and slapped on 3 coats of KILZ primer.

Makes it easy to clean, easy to notice any problems on the floor and keeps the plants happy I recollect...

 

[badugi]

A completely sealed room will suffocate plants w/o CO2 replacement. Most (if not all) window air conditioners do exchange air...

 

[Philosophelon]

Hey Philosophelon, how big was the room and how many plants where in it when things started to get weird?

The room was about 8' x 10' x 7' -- only eight plants, but they were fairly large -- the canopy was about 5.5' x 10', and ~3.5' deep. The plants were in 10 gal pots with 50:50 coco/perlite, transpiring about 10 gallons of water a day (total) to give you some idea of leaf surface area, the daytime temps were ~75 degrees, with an rh ~40-50 percent.

I should also note that I set up a dripper system when the room was getting full, which cut down my time in there to only 5-10 minutes near the beginning of lights-on most days, to check the pH on my res (its drain-to-waste, and fluctuates little), and give my girls a quarter turn.

So the fact that I wasn't in there breathing and opening and closing the door probably had some effect, too. I may not have had any problem had I opened the door a few more times later during lights on.

Edit: Just remembered -- I was not running A/C at the time!!! This was in the middle of winter (single digits at night) and I had heaters during lights out, but cool tubes (and dehuey) kept the room ~75 degrees without the need for A/C during lights on.