grow tent with carbon filter. still having odor issues. Help RIU brothers

randallv

Well-Known Member
Ok, I have 4' x 4' dr grow tent, with a 4 inch carbon filter (can filter) set up ventilating the tent. I have a 8 inch sun system cool sun reflector with the glass, being cooled with an 8 inch can fan, seperate from the room exhaust. I am still having odor problems it stinks still like a dam skunk outside of the tent! Does any one know what the problem could be? what else can i do to properly nutrilize the odor consistently, with out having to spray deoderizers all the time? Any suggestions will be very appreciated.
 

strangerdude562

Well-Known Member
make sure you have the correct filter for your cubic feet, you can also plug in an ionizer outside of your tents, I heard that those are real effective at eliminating odor.
 

easygrinder

New Member
both, the fan usually matches the filter, if your getting smell your not sucking enough air quickly enough to exhaust the aroma
 

fat sam

Well-Known Member
the fan and filter are fine, what your problem is, is that the fan is pulling to hard on the filter, you see the smells need a little bit of dwell time in the carbon to remove the smell, like say a filter is rated at 200 cfm, to remove ALL the smell you should only pull like 150 cfm through it, i had the same problem with my tent until i got a speed control for the fan, i reduced the speed by about 25% and now you cant smell a thing, i think i saw them on htg for like $30
 

randallv

Well-Known Member
the fan and filter are fine, what your problem is, is that the fan is pulling to hard on the filter, you see the smells need a little bit of dwell time in the carbon to remove the smell, like say a filter is rated at 200 cfm, to remove ALL the smell you should only pull like 150 cfm through it, i had the same problem with my tent until i got a speed control for the fan, i reduced the speed by about 25% and now you cant smell a thing, i think i saw them on htg for like $30

I bought a speed control a while ago. It is the kind that you have to wire to your fan. I cant figure out how to hook it up to the fan, are you familiar with how to hook these up???
 

randallv

Well-Known Member

mikecar312

Active Member
i think he's right too. what cfm is your 8" can fan? there's a 500cfm and a 700cfm version (i can't remember the exact numbers). either way, you're fan is probably too strong for your little 4" filter (probably rated for 200cfm). the speed controller should work.

was it 2 months of flowering or 2 months of veg and then you started to notice the smell as they got bigger? if thats the case, you might have been pulling too much air since the beginning and the carbon filter wasn't working.

let us know if the speed con. fixes the problem.
 

randallv

Well-Known Member
The fan is a 4 inch eco plus inline fan. I think its like around 200 cfm. They have been flowering for about 2 months now, started getting worse the further I got in to flower. Thanks for the help man. I will let u know if the speed controller helps. I just got it about 6 hours ago. Now the lights are off. So tomorrow I should be able to tell if it has made a difference.
 

mikecar312

Active Member
oh! a 4" fan changes things, that should work perfectly with your carbon filter. i thought you had an 8" fan, so a speed controller probably won't work for you because you might not have enough cfm's pulling threw the filter with the reflector with 8" duct holes in between.
maybe, you can position the filter>fan>hood>exhaust so the fan is pulling air from the filter and pushing the hot air out of the hood then out of the exhaust.
 

patlpp

New Member
Is the 4" fan sucking air from the carbon filter ducted and exiting the tent? I had the same problem so I mounted the carbon filter up high and attached the fan but than just let the air exit within the tent. This will re-scrub the air over and over. It is true, if the thickness of the carbon is small, like the cheap ass HTG 4" filters, than you need to slow the air down. Only the big boys like the can 33 with 2"carbon can handle the higher cfm's. I run my 6" carbon at about 150 cfm in the recirculating method just mentioned. To introduce fresh air, I have a damper attached to my light exhaust that pushes a portion of the light's air into the tent. My light air is completely segregated like yours. As a result of all this, I have a very slight positive pressure in the tent so some air is escaping thru the lower vents statically. Now you would think you would smell something because air is escaping but nobody can smell a thing. We would be out all day and than run in and smell. Nothing. This works so well for me that I am confident I can use CO2 with minimal loss.

I tried the method mikecar above suggested but with a cheap filter, it still stunk.
 
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