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Air exchange question??

weednurd420

Well-Known Member
Should my fan that is pulling air out be moor cfm then my fan pulling air in?? Also my room is 2ft whide 2 ft long and 8 ft high what size cfm fan do I need?? I have a 200 cfm cardon filtrer a 200 cfm fan for my filter and 200 cfm fan pulling air in is that over kill
 

sunny747

Well-Known Member
Should be pushing more air out than in to maintain negative pressure. More air in equals escaping smells.

In general you don't need air intake in a small space. Just let it pull air from under the door or just add a passive intake hose.

That's 32 cubic feet. You could run the outtake fan at half speed and probably be fine as long as it stays cool enough. Get a fan speed controller for $25. Ditch the intake fan if you can. They use a lot of power and they are noisy.
 

jacksthc

Well-Known Member
newbie lol listen to sunny that advice is spot on, but keep a close eye on humidty as low air exchange can cause high humidty and in late flower run the risk of bud root, the buds will be most at risk when the lights out so if you want to keep your large buds and rot free, keep humidty low, rising temp 10c can reduce humidty by 50%
 

weednurd420

Well-Known Member
Should be pushing more air out than in to maintain negative pressure. More air in equals escaping smells.

In general you don't need air intake in a small space. Just let it pull air from under the door or just add a passive intake hose.

That's 32 cubic feet. You could run the outtake fan at half speed and probably be fine as long as it stays cool enough. Get a fan speed controller for $25. Ditch the intake fan if you can. They use a lot of power and they are noisy.
ok so my 200cfm fan pulling the air out is fine
 
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jacksthc

Well-Known Member
I don't really look at the cfm rating on fans when I buy them ( just buy good qualty rck fans and go by the size) but seems low are you using a pc fan as the exhaust fan ?
can't be pulling the air out the room as I use this for my micro veg box (40 watts of light) and I keeps the box cool
 

weednurd420

Well-Known Member
I don't really look at the cfm rating on fans when I buy them ( just buy good qualty rck fans and go by the size) but seems low are you using a pc fan as the exhaust fan ?
can't be pulling the air out the room as I use this for my micro veg box (40 watts of light) and I keeps the box cool
I'm using 200cfm fan that hooks to my filter as lo as I can find is 170 can but I got to keep my filter so I got to use the 200cfm fan
 

weednurd420

Well-Known Member
newbie lol listen to sunny that advice is spot on, but keep a close eye on humidty as low air exchange can cause high humidty and in late flower run the risk of bud root, the buds will be most at risk when the lights out so if you want to keep your large buds and rot free, keep humidty low, rising temp 10c can reduce humidty by 50%
Not really new just don't grow inside and I'm sick of shit weed loosing crop to mold and shit like that from rain I lost 20 plants out of 35 last year, and this year I lost all, I had 1 good grow in doors but not as good as I like I got a big room to grow in but I'm starting small then going big my small room keeps me high every day for free and that's fine with me I got 16 pounds of regular chronic left to keep food in the fridge and gas in my car so I'm good for a while
 

jacksthc

Well-Known Member
I'm using 200cfm fan that hooks to my filter as lo as I can find is 170 can but I got to keep my filter so I got to use the 200cfm fan
I had my intake fan (4") on the timer with the lights.
6" ruck fan pulling a lot of air out the flower room (1m x 90cm x 1.4cm ).

Didn't keep a check on the humidty, brought a temp/humidty meter and the humidty was very high mid flower( over 80 on some days) cheched the humidty meter with wet salt in a pot and its 3 out some of my meters have been 20 out in the past.
so all meter need to be checked I put a low watt rad in the room and it the dropped 40 with intake fan on 24 hours
joking about the newbie, still makes me laugh about your 200g cola
just keep to the truth and I will give you all the advice I can ( growing in doors in soil) just can't advise about leds, but imo you should try hps/mh they have passed the test of time and have alway givin me great results :) if fan/filter keeps the temp/humidty in range.
Thats great and this will give plants the environment they need














and if I ever grow outside you can call me newbie and tech me how to grow
 

sunny747

Well-Known Member
I'm using 200cfm fan that hooks to my filter as lo as I can find is 170 can but I got to keep my filter so I got to use the 200cfm fan
Its actually best to have your fan lower CFM than the filter. A fan speed controller can do the job just as well though...

I can't even imagine what 16 lbs looks like :)
 

weednurd420

Well-Known Member
I had my intake fan (4") on the timer with the lights.
6" ruck fan pulling a lot of air out the flower room (1m x 90cm x 1.4cm ).

Didn't keep a check on the humidty, brought a temp/humidty meter and the humidty was very high mid flower( over 80 on some days) cheched the humidty meter with wet salt in a pot and its 3 out some of my meters have been 20 out in the past.
so all meter need to be checked I put a low watt rad in the room and it the dropped 40 with intake fan on 24 hours
joking about the newbie, still makes me laugh about your 200g cola
just keep to the truth and I will give you all the advice I can ( growing in doors in soil) just can't advise about leds, but imo you should try hps/mh they have passed the test of time and have alway givin me great results :) if fan/filter keeps the temp/humidty in range.
Thats great and this will give plants the environment they need yea no 1 will ever grow a 200 gram cola I was just joking kuz they did not believe me im not sure if u did or not I did cram 3 plants in there and let them do there thing and they sure did lol, I was thinking about growing 7 small ones put them in milk gugs and veg them shortly after they start to get moor bud faster, the shit I got I do smoke but its not that good to e every 1 I sale to loves it, they don't medicate with it so I don't fill bad sealing it to them...but me I need good shit, I was not sure if a 200w led would grow strong weed or not but the autoflowers was way better then the reg I got. really don't care to much about how much I get just as long as I can keep my self stocked on good shit... If it was not for weed I be homeless so I love weed.














and if I ever grow outside you can call me newbie and tech me how to grow
 

jacksthc

Well-Known Member
I would use a 250w mh in that room and grow a strain like blue dream or super lemon haze, use a good qualty strain

bio buzz fish mix/bloom and epson salt gives you some very high qualty buds.
 

weednurd420

Well-Known Member
I would use a 250w mh in that room and grow a strain like blue dream or super lemon haze, use a good qualty strain

bio buzz fish mix/bloom and epson salt gives you some very high qualty buds.
but my 200w led dose way better then my friends 300w hps, he said he don't do much better with a MH light, he has had 2 grows sense my last and still has not done better then I have... im gonna stick to led, less watts less power moor bud haha
 

*BUDS

Well-Known Member
Bullshit, there is no way a 200w led can outperform a 300w hid not a chance in hell. Poor growing technique was the reason.
 

jacksthc

Well-Known Member
Go for it fellow, just remember leds a new technology and the hype has not warn off yet, only last year everyone was going on about these ufo 90w leds ment to pull more than a 600w hps lol.

Hps will give you a better yeild than a mh but if you want your buds covered in crystals, mh is the way to go.

My local grow shop stopped selling leds becase they got so many complaints about the buds being to airy, so he stopped selling them !!

anless you buy the really expensive ones its a waste of money
 

weednurd420

Well-Known Member
Bullshit, there is no way a 200w led can outperform a 300w hid not a chance in hell. Poor growing technique was the reason.
funny diamond series led say there 200w led lights with the 3 watt creed chip replaces a 300 w hps, I can also show you youtube videos of the same light I got out growing a 300w hps
 

jacksthc

Well-Known Member
He was selling the wrong ones then.
The probem is budman there is so much hype and profit to be made out of equipment, lights, seeds ect for growing weed it becomes very diffecult to know what to believe

I have been on the grow forms for years (old user, forgot login details) and I rember talking to you a few times and you make a lot of sense

have you done a side by side test to compair leds vs hps
and got some good results from the leds ?

I don't believe videos on youtube saying they have pulled 10oz's or 20oz's from a 600w.
If they take the pic from the right angle and stack the weed up you couldn't tell the diffence
 

budman111

Well-Known Member
The probem is budman there is so much hype and profit to be made out of equipment, lights, seeds ect for growing weed it becomes very diffecult to know what to believe

I have been on the grow forms for years (old user, forgot login details) and I rember talking to you a few times and you make a lot of sense

have you done a side by side test to compair leds vs hps
and got some good results from the leds ?

I don't believe videos on youtube saying they have pulled 10oz's or 20oz's from a 600w.
If they take the pic from the right angle and stack the weed up you couldn't tell the diffence
I have never done a side by side but I have done HPS in the past and LED now (Vipar B series) and I can get on average 5-6 oz per plant on a 4 weeks veg and 8-9 weeks flowering time and HPS was almost the same harvest weight but with led you have less electricity less light pollution, less heat which leads to less intense smells...and yes some LED are really shit, research on chip diodes, drivers and such is really needed, Vipar is far from the best but they are here in UK and suits my budget needs nicely..
 

weednurd420

Well-Known Member
I have never done a side by side but I have done HPS in the past and LED now (Vipar B series) and I can get on average 5-6 oz per plant on a 4 weeks veg and 8-9 weeks flowering time and HPS was almost the same harvest weight but with led you have less electricity less light pollution, less heat which leads to less intense smells...and yes some LED are really shit, research on chip diodes, drivers and such is really needed, Vipar is far from the best but they are here in UK and suits my budget needs nicely..
some led lights do suck bad I had a 200 w led from chine I never used it my self my friend did and the buds was small as fuck but they was strong, I only beat my buddy by 12 grams he had 300 w hps and I had the 200 w led we ran the same plants and he has been growing for over 13 years in side, I have noticed led lights grow Harrier buds that are a little better then hps, and yea my led light only ran my bill up like 15 bucks moor,
 
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jacksthc

Well-Known Member
I have never done a side by side but I have done HPS in the past and LED now (Vipar B series) and I can get on average 5-6 oz per plant on a 4 weeks veg and 8-9 weeks flowering time and HPS was almost the same harvest weight but with led you have less electricity less light pollution, less heat which leads to less intense smells...and yes some LED are really shit, research on chip diodes, drivers and such is really needed, Vipar is far from the best but they are here in UK and suits my budget needs nicely..
leds do sound good with the less heat and less electria but I can't seem to find any information on the light pentrating the canopy, some of my desent buds can be 12" deep
how far can the light pentrating the canopy with leds ?
 
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