Grow Room Do you HAVE to have exhaust fan/filter?

[MassMom]

Hi Peeps!! Just a question for the masses. Do I really need an exhaust fan/filter setup? My home is an open concept situation. I have an HVAC system that consistently keeps my home warm in winter and cool in summer..its always 70 degrees. My tent stays a consistent 78 degrees with my light, and I never have a humidity issue. I have a passive vent open on the bottom right of my tent, a passive vent open at the top left of my tent, and a strong rotating fan. Growing is legal in my state, and my family actually enjoys the smell of cannabis. I do have an exhaust fan/filter setup in the tent (which is not vented outside, it is just vented back into house), but I have never turned it on. I also have never experienced any mold issues in my grows. However, am I doing an injustice to my plants?

XOXO
Mom

 

[Bruce Campbell]

Do I really need an exhaust fan/filter setup?

Filter - No, it's just for people where smell can be an issue. Even in legal states, some people prefer not to advertise to neighbors that they're growing as a security issue. But, if that's not a problem for you, then you can go without.

Active (exhaust fan) vs. Passive (just open vents) Ventilation - Technically, you do need to give them some fresh air so that they don't run out of CO2, but that's only around 1-2 cfm/plant (compared to the nominal 200-300+ cfm from an exhaust fan). If just passive venting is keeping your tent cool enough, and there's enough circulation between the house and lung room, then you probably have enough ventilation for CO2.

If you wanted to double-check, you could get a CO2 meter. Just be aware that you want a greenhouse-type meter that measures low CO2 levels. Most of the cheap "indoor air quality" CO2 meters only measure elevated CO2 levels, not reduced CO2 levels. Or, you could just get one of those small 3-in USB desk/stroller fans and put it in one of the tent ports just to be sure.

But, personally, I probably wouldn't bother and just keep running as-is. If you can smell your plants, then you probably have enough tent ventilation to provide adequate CO2.

 

[MassMom]

Filter - No, it's just for people where smell can be an issue. Even in legal states, some people prefer not to advertise to neighbors that they're growing as a security issue. But, if that's not a problem for you, then you can go without.

Active (exhaust fan) vs. Passive (just open vents) Ventilation - Technically, you do need to give them some fresh air so that they don't run out of CO2, but that's only around 1-2 cfm/plant (compared to the nominal 200-300+ cfm from an exhaust fan). If just passive venting is keeping your tent cool enough, and there's enough circulation between the house and lung room, then you probably have enough ventilation for CO2.

If you wanted to double-check, you could get a CO2 meter. Just be aware that you want a greenhouse-type meter that measures low CO2 levels. Most of the cheap "indoor air quality" CO2 meters only measure elevated CO2 levels, not reduced CO2 levels. Or, you could just get one of those small 3-in USB desk/stroller fans and put it in one of the tent ports just to be sure.

But, personally, I probably wouldn't bother and just keep running as-is. If you can smell your plants, then you probably have enough tent ventilation to provide adequate CO2.

Thank you hon. I do have a small fan on the floor "pulling in" from the bottom passive intake opening. (guess its not so passive? LOL) Cool....

 

[Badfinger]

Your a veteran grower compared to me. My first grow this past summer was in a closet, and when I was in the drying stage, our house smelled so strong of what I assume was the chlorophyll breaking down and releasing ammonia that the wife and I felt sick from it, there was nothing pleasant about it.
That's when I decided I needed some kind of filtering system, which naturally led to a tent and everything that goes with it.
How did you deal with that smell after all those grows with no filter system?

 

[Olderfart]

Filter - No, it's just for people where smell can be an issue. Even in legal states, some people prefer not to advertise to neighbors that they're growing as a security issue. But, if that's not a problem for you, then you can go without.

Active (exhaust fan) vs. Passive (just open vents) Ventilation - Technically, you do need to give them some fresh air so that they don't run out of CO2, but that's only around 1-2 cfm/plant (compared to the nominal 200-300+ cfm from an exhaust fan). If just passive venting is keeping your tent cool enough, and there's enough circulation between the house and lung room, then you probably have enough ventilation for CO2.

If you wanted to double-check, you could get a CO2 meter. Just be aware that you want a greenhouse-type meter that measures low CO2 levels. Most of the cheap "indoor air quality" CO2 meters only measure elevated CO2 levels, not reduced CO2 levels. Or, you could just get one of those small 3-in USB desk/stroller fans and put it in one of the tent ports just to be sure.

But, personally, I probably wouldn't bother and just keep running as-is. If you can smell your plants, then you probably have enough tent ventilation to provide adequate CO2.

Beat me to the draw, and did a better job than I could mate. I really appreciate your separating the issue of CO2 supply from the issue of heat in the tent. I get tired of hearing that my plants "breathe" multiple cubic feet of air per second - they don't, period. Ventilation requirements specifically for CO2 delivery are a fraction of those needed to deal with temperature and humidity. As long as those latter conditions are dealt with effectively, plants should get all the CO2 that they can use, at least for most of us and our setups.

As to the smell bit, I would not be without a filter. It is an amazing thing how potent some strains can be, especially when their "exhaust" is confined inside one's home. In my first outdoor grow, my dearest found the odor of three Pink Kush plants objectionable when she was working in the yard some twenty meters away. Any neighbour with a nose could probably tell what was up, as could any dog walker going by, and more to the point, any teenage stoner who might develop an interest in the product. Even in legal jurisdictions, advertising the presence of cannabis plants is a significant security risk.

Happy filtering peeps.

 

[wwwillie]

The only thing I can think of is that you get used to the smell. Always amazes me how potent it gets when I’m away from it long enough to notice. So a stranger coming into your home may find it a bit strong.

 

[GreenBean]

Even in legal jurisdictions, advertising the presence of cannabis plants is a significant security risk.
Happy filtering peeps.

This right here. I’m always asked why I bother filtering because I’m in a legal state.

Thieves would be one concern, although my least worrying- knock on wood.

Nosy neighbors being my biggest. Once they know, they know. And maybe my neighbor directly next to me does know? But do I want the nosy neighbor 2 houses down who loves to stir up shit knowing?

 

[Olderfart]

This right here. I’m always asked why I bother filtering because I’m in a legal state.

Thieves would be one concern, although my least worrying- knock on wood.

Nosy neighbors being my biggest. Once they know, they know. And maybe my neighbor directly next to me does know? But do I want the nosy neighbor 2 houses down who loves to stir up shit knowing?

uh, no, you don't. Word would inevitably get out via either neighbour, and once out, there is no taking it back. The first explore of your home to find the weed will not be the last. The incentive of potentially ounces of free weed is a large one in some quarters. High risk tolerance, and low funds makes for breakins. Even if you stopped growing, the word would still be out there. Then there is the issue of what your house insurance policy might have to say in the matter...

Bottom line is that the fewer that know the better.

 

[Teuffelhound]

Excellent response @Bruce Campbell

 

[GreenBean]

uh, no, you don't. Word would inevitably get out via either neighbour, and once out, there is no taking it back. The first explore of your home to find the weed will not be the last. The incentive of potentially ounces of free weed is a large one in some quarters. High risk tolerance, and low funds makes for breakins. Even if you stopped growing, the word would still be out there. Then there is the issue of what your house insurance policy might have to say in the matter...

Bottom line is that the fewer that know the better.

Not to mention knocks (or kicks) on the door because said nosy neighbor has called and insisted that you have a massive operation going. Which is another reason I no longer go even one plant over my legal limit. Nor will I be growing anymore 12’ tall photos outside again. In the scheme of things, I’m just The Little Guy. And in my experience, us little guys/gals are usually the ones to get fucked.

I always run a filter in the indoor tent. Didn’t run one in the garage 4x4 because honestly it didn’t smell bad. Especially in cooler weather. But after putting the Sage Scout in there, and being able to smell it 30’ away, I just had to. And the smell is gone.