passive intake question +rep for goods answers

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tyler666

Active Member
i am going to be growing in a backyard mother-in-law cottage in a 3.5ft x 3ft x 7ft closet.

now this is no ordinary closet, it is an add on so i can vent and exhaust straight to the outdoors. (I AM USING A 400W HPS AND A 300CFM, if that makes a difference.)

my question is this

should i put my passive intake on the bottom of thecloset door, taking air from inside the cottage?

or

should i put my passive intake on the side of the closet taking air from outdoors? (opposite side of my exhaust fan of course)

now the cottage currently has no A/C or anthing so i think the air would get a little stale in the cottage, wouldnt it? if i installed a wall A/C would it inprove air quality?

thanks in advance
 
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kno

kno

Active Member
How hot will it get outside during your grow?

I would take air from the cottage, the temp will be more consistent.
 
kno

kno

Active Member
100F is too hot. If it gets above 85 in the cottage I would put an air conditioner in there
 
K

Keenly

Guest
tyler666 said:
i am going to be growing in a backyard mother-in-law cottage in a 3.5ft x 3ft x 7ft closet.

now this is no ordinary closet, it is an add on so i can vent and exhaust straight to the outdoors. (I AM USING A 400W HPS AND A 300CFM, if that makes a difference.)

my question is this

should i put my passive intake on the bottom of thecloset door, taking air from inside the cottage?

or

should i put my passive intake on the side of the closet taking air from outdoors? (opposite side of my exhaust fan of course)

now the cottage currently has no A/C or anthing so i think the air would get a little stale in the cottage, wouldnt it? if i installed a wall A/C would it inprove air quality?

thanks in advance
Click to expand...


what we call "stale" air we can sense is full of co2


the plants love that


put your passive intake as far down as you can , put your exhaust through one end of your light, out the other, and outside
 
T

tyler666

Active Member
Keenly said:
what we call "stale" air we can sense is full of co2


the plants love that


put your passive intake as far down as you can , put your exhaust through one end of your light, out the other, and outside
Click to expand...

thank u all +reps. now if i were adding co2, and im exhausting though my hps. can i add co2 when the light is off, and i turn the exhaust off. this would be the only way i think right?
 
naked gardener

naked gardener

Active Member
You really don't want to run the co2 when the light is off--as far as i know plants only ablsorb co2 during light hours---and they will actually create it during dark

If you do not use co2 enrich, I would suggest intake from outside covering your intake hole (at bottom of room) w a quality filter--and add some temp. control...

BUT...inside air is not so bad either for intake-- I would just try keep it pretty fresh...

Good luck--I just set up my intake/exhaust recently and found lots of useful info on here
 
T

tyler666

Active Member
so you cant add co2 at night?? is this true

would it be better to add it with the light on and exhaust or with the light off and no exhaust? or it is a wash


or do i even need it in my size grow room? (3.5 x 3 x 7fthigh)

thanks to all +rep
 
The Good Doctor

The Good Doctor

Active Member
Outside air generally is cooler, fresher and has more abundant CO2, but. . . if you have a water heater near it(that used natural gas) you could vent from there to get CO2.

If you don't care about CO2, get the air with the collest temp(unless you are in Montana or some cold place like that.). As a general rule of thumb, put cold air in and the bottom of the room, and hot air out at the top of the room. Heat rises and cold sinks, so take advantage of this natural flow to create your passive air flow.

Whatever it takes to create 72-78 degrees, is what will work. NOTE, if you take in air from the outside, at the very least use some panty hose to filter it. Remember, every bug and moth and mite will want in! ! ! Prepare accordingly.

Also don't forget, one thing about usuing outdoor air, spores, pollin & moisture also occur! So use ah filter of some sort!
 
The Good Doctor

The Good Doctor

Active Member
Naked Gardner is generally right. CO2 is primarely absored during the light cycle, while photosynthisis occurs.

If you have a co2 bucket puck or boost system, you will generally not have control of this. Only if you are running a tank system or generator will you have this level of control.

The cheapest and easiet two ways of adding CO2 are the CO2 pucks(just put in 3 table spoons of water). Or the CO2 boost bucket. The pucks are 5$ each and the bucket is 150$

The difference is that the Bucket lasts around 2 to 3 months. The puck is only good for one light cycle. So for the price of 30 pucks, you get the boost bucket.

The next step up, is adding a CO2 tank & regulator and meter. Much more expensive, between 750 and 1200.

The next step up from that is the Generator, this requires, a natural gas hookup/or propane. A meter, a regulator, some length of piping/tubing etc. between 900 and 1500 to do right.

If you are using a small area ala Tent or Closet, the pucks and boost buckets would be perfect for you! You really only need the big boy setup in big boy setups!
 
naked gardener

naked gardener

Active Member
For real...plants consume CO2 in the process of photosynthesis which only occurs during the day when there is light. During this process the stomata open to absorb CO2--at night the stomata close and the plant will use the stored oxygen that it did not emit during the day for it's night-time metabolic purposes--and during respiration at this time it will actually release co2 instead of oxygen

During day she breathes in co2 & breathes out oxygen--during the night--it is the opposite..

you can ask around, google if you want--but i would not steer you wrong :peace:
 
The Good Doctor

The Good Doctor

Active Member
I agreed with you naked gardner. . . .

The one super cheap way to do CO2, is to vent to your room from a water heater closet, if it uses natural gas, there is a constant build up of dangerous CO2 gasses, but for plants, CO2 is gold! . . .

Other than that, see previous post about pucks vs buckets vs tanks vs generators
 
T

tyler666

Active Member
yea im not by a water heater so i dont really have any viable options for adding co2, except for adding 2 exhausts(1 for hps, and 1 for room) and turning off the room exhaust.

are your temps normally higher when adding co2 since the exhaust is off?
 
The Good Doctor

The Good Doctor

Active Member
CO2 will always make the room hotter, and you want it that way(think about the Earth, green house gasses,effect etc.). The plants do best taking in CO2 at around 81 to 86 degrees.

Leaving the lights exaust off, will not create any significant CO2. Buy a puck or a boost bucket. 50$ worth of pucks should last between 10 and 15 days depending on the rate you get, and they do work. A CO2 boost bucket lasts between 2 and 3 months! ! ! In the size area you are talking about, a single boost bucket would really kick your plants into another world.

CO2 can boost your grow up to 30% percent by itself. Thats almost a 1/3. If you are planning on having more than 2 ounces grown already, that means a 17 gram increase for 150$. If you are planning on a 4 ounce harvest(w/o co2) you would see an aproximate 35 gram increase w/ CO2. Thats over an ounce for 150$. Totally worth it! ! !

Both the pucks and buckets do not require any gauges, readers, meters, or regulators. So if you can, use them. Space will not be the issue in using pucks or boost buckets, only money would be. But it is worth every penny, if you can!

One other cheap way, but this is VERY DANGEROUS! ! ! And requires CONSTANT MONITORING! ! ! Using a candle box, or sterno box. Simply having sterno cans, or candles burning in the room, will create a significant level of CO2. BUT BE PREPARED, WATCH IT CONSTANTLY(I MEAN CONSTANTLY), if you choose this method. Or you will burn your house down. Personally, cost verses outcome dictates, pucks or buckets(because even sterno and candles cost money! ! !

If you can make it happen, CO2, will make everything about your crop better and bigger, it is worth doing ! ! !
 
The Good Doctor

The Good Doctor

Active Member
** NOTE ** If you kill your exausts, your just leaving old used up air, not CO2, in the room! So this method is not the best. At the very least brining fresh air into the room, and constantly exausting it, creates an air flow. If the air isn't flowing, and the leaves aren't moving, then they are not getting CO2. A plant, can use all the available CO2 in the air(and 700% more than that) in an area of about 6"s from the plant, in a very very short amount of time. So creating dead air in the room, only makes this effect worse, not better. ** end note**
 
naked gardener

naked gardener

Active Member
The Good Doctor said:
I agreed with you naked gardner. . . .

I know Good Dr...i started my reply and got sidetracked by food--so i didn't see yours before i posted :peace: (which made my post a little redundant for the thread, too :oops:)

moving on...

for heat concerns and co2--you can set up a system on some timers shutting off exhaust long enough for co2 to fill room--and a few minutes to absorb--then turn exhaust back on--

but that can get expensive..regulator, digital timers..ppm meter (if you so choose)--etc

from what i understand--with co2 enrichment plants can tolerate a lil higher temps--however, at the same time, when temps get higher they cannot absorb as much co2...it is a fine balance
Click to expand...
 
naked gardener

naked gardener

Active Member
Hey GOOD DR--have you ever, or know anyone who has, used the buckets and saw a measurable difference? I have lately been curious about them--except I pretty much have constant air exchange (bc my exhaust has carbon filter attached and I need it working 24/7) how do you think that would affect the effectiveness or longevity of the bucket?

Also--is it considered bad riu etiquette to ask a question in someone else's thread? If so, my apologies tyler666...
 
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