How long can plant's go without ventilation?

I'm sure this is also depends on grow room size and plant count, but the crawlspace I use is about 4x5x12' with hopefully all of it filled in with plants. Currently I did not add an intake/outtake fan but every morning I open my grow space for fresh air (+ a few hours the odd day lol). So roughly 6 hours during veg & 12 hours during flower the room gets no fresh air (fan is always on though). Would this cause my plant's to hermi or do anything severely bad? Thanks in advance :).
 

Way2-High

Well-Known Member
4’ x 5’ x 12’ ? That’s a big area, if it’s filled with plants moisture will definitely be a concern without ventilation. Not to mention heat from lights.
 
4’ x 5’ x 12’ ? That’s a big area, if it’s filled with plants moisture will definitely be a concern without ventilation. Not to mention heat from lights.
I have a de-humidifier inside always turned on also & like I said I usually open it right when lights turn on. Even when I forget a few hours, the temp inside never goes over 73F (I use CFL's & this might increase a bit in summer), the humidity spikes a bit more though but never passes 65% (at lights out). I was more worried the plants would suffocate from no CO2 or something lol. Thanks both you, think i'll just try to install one before next grow since this ones already done.
 
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Hydro4life

Well-Known Member
Should be fine for now imo. But growth wont exactly explode. Adding co2 to your room would do the trick. But i doubt that would be your viable option if getting a couple of fans and ducting is still on the list.
 

PURPLEB3RRYKUSH

Well-Known Member
I'm sure this is also depends on grow room size and plant count, but the crawlspace I use is about 4x5x12' with hopefully all of it filled in with plants. Currently I did not add an intake/outtake fan but every morning I open my grow space for fresh air (+ a few hours the odd day lol). So roughly 6 hours during veg & 12 hours during flower the room gets no fresh air (fan is always on though). Would this cause my plant's to hermi or do anything severely bad? Thanks in advance :).
Ive done closet grows, no ventilation b4, plants showed abit of stress but harvest were still good, i had just a fan and heater in their, ran lights at night, open closet door every now and again
 

Hydro4life

Well-Known Member
Constant Fresh air/co2 is obviously best. Off memory once the plants use the co2 in the air and co2 gets down to 200ppm plants will go stagnant. Anything below 200ppm of co2 and plants will start to die. The more/bigger the plants the faster they will process the remaining co2 in the room. The smaller the room the less volume of co2 in the air. My advice is get some air exchange happening asap if your not supplementing co2.
 

DustyDuke

Well-Known Member
For sake of $20 from a hardware store for a cheap vent fan, it’s money well spent it could yield you an extra oz or more. I’ve even seen people use a pedestal fan for venting. I put ducting behind my clip on fans inside my tent, it draws fresh air in the fans basically suck air in you can feel air moving threw the ducting with your hand.
This is a pic of the fan sucking fresh air in this is all I do to get air in I do it to 2 fans
2E2E272B-E803-4A27-A2B8-33D2B26EC8AB.jpegthis pic how to get air out on a budget. I’ve never done this before I did it just for the pic but it worked really well, better the I thought. Though you are pumping unfiltered air out. 62973C9A-942C-4DF7-A975-D38896599A19.jpeg
Here’s how to do it properly carbon filter, fan and silencer (if you are worried about people hearing or smelling it)DAF6D2DA-E6B2-4B16-B00B-8832C4806351.jpeg
 
For sake of $20 from a hardware store for a cheap vent fan, it’s money well spent it could yield you an extra oz or more. I’ve even seen people use a pedestal fan for venting. I put ducting behind my clip on fans inside my tent, it draws fresh air in the fans basically suck air in you can feel air moving threw the ducting with your hand.
This is a pic of the fan sucking fresh air in this is all I do to get air in I do it to 2 fans
View attachment 4324900this pic how to get air out on a budget. I’ve never done this before I did it just for the pic but it worked really well, better the I thought. Though you are pumping unfiltered air out. View attachment 4324901
Here’s how to do it properly carbon filter, fan and silencer (if you are worried about people hearing or smelling it)View attachment 4324903
Ya I'm not concerned about the smell, doesn't seem like with my plant count it will go past the inside of my house. My main concern is sealing the end of the ducting off so no light gets in, yours seem like it would let light in? or whats on the outside? Great advice everyone, just as I figured :)
 

DustyDuke

Well-Known Member
No light gets out of my setup why would I go to the trouble of fan silencer and carbon filter, then not care about light escaping. Make sure your ducting has black on the inside and put 90 degree bend in the ducting helps also 2 even. You will just have to play with it a bit but light escaping is easy to fix
 

Hydro4life

Well-Known Member
Ya I'm not concerned about the smell, doesn't seem like with my plant count it will go past the inside of my house. My main concern is sealing the end of the ducting off so no light gets in, yours seem like it would let light in? or whats on the outside? Great advice everyone, just as I figured :)
Use ducting and like dustyduke said, put a 90 degree bend in. Also a black stocking or similar on the end of ducting helps. Especially on the intake side as it will stop bugs enering tent also.
 
No light gets out of my setup why would I go to the trouble of fan silencer and carbon filter, then not care about light escaping. Make sure your ducting has black on the inside and put 90 degree bend in the ducting helps also 2 even. You will just have to play with it a bit but light escaping is easy to fix
Not exactly sure what a silencer is yet. Figured you obviously had it light proof :) & thought the carbon filter was only for smell (+ the light proofing it also). I'm also worried about just 1 90 degree angle, I already did something like that for a grow box, looking in the hole inside the box I could still see lots of light (the inside of the tube was black & about 7 feet long). Last thing too, I was worried if I don't use a strong fan, some sort of fabric like on your filter (or a black stocking, tyvm Hydro :)) would strain the fan (like I had with a 5 inch computer fan before lol). Sorry if I sound really new, I'm sure I could play around with it as you said though. Cheers again :).
 
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