Been growing for a good few years now, and I was always taught that to grow plants in flowering you had to use ventilation roughly changing the air 20 times an hour.

I was at a friends house and he wanted some advice and before I could say anything I was pressented with his Gorw.
He was vegging his plants and I noticed there was no ventilation, His plan is to get a 400w hps and just flower them.

Can you grow with out ventilation?? and if you can what differance is there to weed that has been grown in a ventalated room??

I was under the impression you needed ventilation to stand any chance of getting good crystals

you can grow in early veg and keep mums wil very little ventilation, but to to a whole grow with none means you are not gonna get very good results. Air exchange is just as crucial as what your feeding them

If you get an aircon and CO2 sistem then yes mate.Its too much hustle for me i stick to normal rkv..i hate the noise it makes

first grow i did had no real ventilation it was in bathroom so i turned small vent from time to time to suck up the smell,it was a nice smoke only 4 plants and 250w during winter...its possible

e2a it yielded maybe ounce dry and my hole apartment smelled niceeee

Long stangly stems.
Huge heat problems.
Stale air - mould would love it.

The grow I was shown was 12 plants in a drobe with a 250w hps and that was it. He said he kept the door open during the day and sometimes put a circulating fan on it. 2 of his plants looked really good and healthy but the rest were only a week old and looked ok.

how much did you get off yours with only a 250w and was it a good high/stone you got?

weedio I thought mould would be a factor also but wasnt a 100% sure

Depends how big the room is really I've grown with ventilation only into the room the tent was in and the window slightly ajar but just slightly and they did alright I suppose (~8oz 600w) but kept getting LSF. They do a hell of a lot better with ventilation though and no LSF.

nice smoke as mentioned above but that were beginings i didnt now thaat i need rkv back then,i didnt now what cutting and man i regret it till today it was perfect smelly canna /Plants were skinny as heck no mold, 3m2 bathroom

e2a not that i would recomend you to do that i was just un informed back then /smell,neighbours/heat,sick plants/aka multiple problems that i didnt even notice back then/but got my ounce and boy it was sweeet and smelllllllly

Not effectively, no. Especially not with a 400w light

Your mate needs a 125mm RVK at a minimum really. Might get away with a 100mm with a nice airy space

Should be fine in veg (with an oscillating fan and plenty of airy holes) but flowering/using a 400w will be fookin impossible in a drobe.

Hi Nu Jersey
i have a small drobe i built for my little ones and seedlings that has no real ventilation at present but this is only for first few weeks before they move on into the tent, this is partly because i want a higher humidity for the first stage and it seems to be doing the trick at present.
However i wouldnt think u could ever achieve the maximum out of your crop with no ventilation, even a 250 hps must build up a fair amount of heat if left to warm the same stale air all day and we all know our girls like a bit of air flow.

Photosynthesis : the synthesis of complex organic materials, esp. carbohydrates, from carbon dioxide, water, and inorganic salts, using light as the source of energy and with the aid of chlorophyll and associated pigments.

No ventilation = no (or little) carbon dioxide = no (or little) synthesis of carbohydrates = no (or little) growth

It's not rocket science, but it is biology

I guess it is possible (to grow with minimal air excchange) but you are embracing problems and sub-optimal growth. I have certainly found that it is the thing I initially underestimated the importance of. That's not to say I opted for no extraction being aware of simple biology. However what I did get wasn't sufficient so I had to buy again so I would say the extraction you are thinking you'll get away with - go one size bigger. It is just as important as lights and food.

EDIT for clarity

I am hoping for his sake that he does get something. I would hate to put in all that time and effort and not get much or anything in return,

I kinda guessed it would be a waste of time growing with out ventilation but I have heard from a few people now that you dont need it.
1 of them was I guy who I was growing with, he kept on saying we should be getting more yeild than what we were and he would say that his other grower pal gets 25 oz a plant per auto pot (hydro) in a drobe (not designed for growing) and it would have no ventilation and a 600w hps. He was trying to rubb it in my face.
But I laughed at him and said "see the more you say stuff like that to me, the more it says that you havent learned anything from me or what we are doing".
That guy is now of growing with his no ventilation in a drobe buddies. and in alot of ways I am glad but most of all that you all are confirming for me what I was always lead to believe and that he will find out the hard way hopefully

but for my m8 that just started in a drobe I am not so happy for as he may need to invest in ventillation I will just need to keep tabs on him to see how he gets on

He was lying mate.

To grow effectivly as eri said on post up you need 350ppm of CO2 in your growroom at all time so statment that you dont need ventilation is false.I told you what i did in beginings and it was much worse than now in fact i cant compare yield and health of my plants back then and today.There are growers on board that grow canna over 40years and they all use RKV or Co2 sistems today and they dont use it for nothing ,tell your mate that

for my spelling

25oz, 600w, in a cupboard, hmm. I smell a pink beard around here somewhere.

25oz per autopot I believe that's a world record you should ask him to write to Guiness although he'd probably ask for a free pint from the sounds of it.

Every week there is one that claim to get 1.5 up to 2.0 gr/w,my ex dealer clamed it to thats why i had to dry canna that i bougth from him for 2 weeks more or smoke it wet

Funniest title to a topic I've read yet.


There is no such thing as plant growth without ventilation. Period. What you are talking about NJD is passive ventilation.

The better the ventilation, the better your plants do and the less chance of nasty molds, funguses and slimy bugs invading your grow and ruining your crop.

Not to mention that odor control is exceptionally hard to control.

For confined areas, passive ventilation can work for very small grows but is generally not advised.

This is a good topic exporing the the rapid and negative effects of no venting on a grow......

Disaster's happen....

The point you make about them getting 25 oz and it being wet is quite true, everytime I have seen someone who bought a bit off of them, had to dry it first before smoking it as it was so wet it wouldnt burn

The thing I now find most funny is how adamant they are that this is the way to get 25oz a plant minimum, they are now telling me it is all in the nutrients they use and that they have figured out how to feed it so that it gives that much. They use advanced nutrients whole range. Never used that brand just canna myself. they say it is a 7 part nutrient solution. in a 50l homemade auto pot they dont use a water heater. they use a truncheon to gage the strength, in all they say you need barely no equipment just a light and an auto pot

the more I thin about what they are saying the more I laugh but the thing that makes me wonder is how adamant these guys are. When I say no you need ventillation its like I just dropped the funniest joke thet heard all year and rubbish me as knowing nothing

Oh and if I was to tell them it was a world record these guys would be on the phone as soon as I said it. I think they are so far up there own arses that they say these things to make them look like grow kings. they really do believe these things almost like a religion

I used to grow with piss poor ventilation.
It was one of those over-stairs cupboards and I opened it right up into the loft. (neighbours chain-smoking dog owners.)
For some daft reason I left in a shelf half way up - never actually used the vegging space above much ...

So I relied on leaky doors and a gap up the back of the shelf to convect the hot air up to the draughty loft.

When I finally took the shelf out and fired up both 250s I got a reasonable yield in the two grows ...purely with convection ...

My current one is pisspoor I'm afraid - 1 foot "sump" emptied by a 4 inch kitchen fan through the wall - no filter

I think I'm a reasonably competent grower now generally after about 14 years, so I know I ought to be doing even better than I am.

But I'm a modest toker and if I was too successful, my next grow would be so much further awy.

i stuck a couple of unknown starains in my wardrobe 3 years back before i knew anything aboout growing

no ventilation no nutes apart from that in the compo and a 250 external seurity hps light

i had to leave the wardrobe door open so the plants didnt cook but ended up with 1.5 ounce off each

so i guess the answer is yes you can grow without proper ventilation but it will have a huge effect on your yield or chances of even getting that far

It's possible, just not very efficient.

I run a 400w in a cupboard, doors open for lights on. (but i'm literally in the middle of doing the leepy method on my shiny new 6inch RUCK )

I think the only thing in my favour is the size of the cupboard - about 7 cubic meters all in - helps spread the heat around i guess. It runs 27 lights on, 22 lights off.


Best result I've had is still the Master Kush - got 140 odd grams, so about 0.35 g/W.


Can't wait to get the fan in though




Sub

No expert grower but think it just depends on size of room or space and how often your in there opening doors and or leaving some fresh air into the space like others a lot more expieranced have said with out proper intake and venting wont get what u would in its natural enviro [outside] but can get some quite good results depending on size of room n air circulation ! suppose just depends what you willing to get out of the work u put into it in my case anythings better than dealing with a dealer just being self reliant is its own reward !

That reminds me of something I found really funny :

haha 25 0z of wet moldy leaves more like

don't listen to them m8, you're right

I had a DR 120 delivered on Monday, but prior to that for the last five years I grew 2 plants in a wardrobe with double autopot tray, a 400w HPS ,and a clip on fan. The drobe was near a secluded tilted window covered with a thick curtain . I had fairly good results, but you have to watch the mold. On my last grow I had a small bit of bud rot, but now I know the early signs to look for and lost very very little of the crop (no more than a few joints) You could always use bud rot stop a few weeks before harvest to counter the problem.

The wardrobe door would be open when the light was on and obviously closed in the dark period, although in the winter if you're not using the room that your growing in you could just leave the door open at all times if your dark period is actually when it's dark outside.

I've still not got ventilation for the DR120 yet, but have just started a new grow and will get something sorted by the time I start flowering in about 5-6 weeks. As the tent is in my bedroom the main concern for me is the extractor noise when I'm sleeping.

What about the smell factor? When they start stinking the door might need to be shut to control it (possibly). Won't that cause even more problems??

Well I've yet to use a carbon filter with only two plants, but there have been plant smell issues in the past, especially in the summer. It just depends on your location I suppose. Maybe some people can get away with no carbon filter.

I've gone from 2 plants to 6 plants this time, so ventilation and odour control will have to be sorted by the time I flower. My main issue is the extractor noise.