Smelling the flowering grow despite having a carbon filter

BadlyDrawnBoy

BadlyDrawnBoy

Active Member
I've got a 6" fan and 6" carbon filter inside a 4x4 tent. It's in late flower and I'm starting to smell it outside the tent, even though I'm using the carbon filter. I have the fan turned up half strength and the carbon filter is new, this is the first grow I'm using it with.

Is it typical to still smell a bit on the outside of the tent? It's odd because when i stick my face at the end of the duct exit from the fan, I smell no sign of cannabis. Yet when I open the door to the basement, I smell it immediately.

I was thinking of trying an additional odor control method. The ona brand sounds like it works, but I'm very sensitive to smells and I'm afraid it will be irritating to me. Synthetic smells are usually a no go for me.

The smell isn't a huge deal, I live in an isolated area and we rarely have visitors, and you only smell it if you open the basement door. But still...I'd just rather the filter did it's job and there was no smell. Odd because I smelled nothing up until a few days ago, then it got much stronger. I know the filter is working because no smell is noticed on the outer end of the exhaust. I turned the fan speed up a bit, thinking if it drew more air through the filter, it would be more effective. No noticed improvement yet.

Anyone else experience this despite having a carbon filter? I'm only growing 2 plants for medical use
 
SouthCross

SouthCross

Well-Known Member
An 8" inline with a 8" carbon will fix the smell issue. I use an 8" on a 2x4x7 tent. I too would get a room smell using a 6" blower and carbon. It took my cfm to vacuum out the smell. I have no problems controlling humidity will the 8".
 
BadlyDrawnBoy

BadlyDrawnBoy

Active Member
So having the fan speed at a higher speed would help then? I only have it set to half. I'm definitely not upgrading to an 8", the smell is only apparent now that it is in the late flowering phase. I've had the 6" on a very low setting for the tent and it was plenty. Maybe I will keep upping the speed and hope it helps
 
Kerovan

Kerovan

Well-Known Member
Yes, smell will always be an issue. No matter what you do the carbon cannot absorb it all. I'm not sure if upping the fan speed will help or not, you can try. People who say they don't smell it are just acclimated to the odor. Get a lot of glade air fresheners around the house and a cheap low power ion air filter to help.
 
Buba Blend

Buba Blend

Well-Known Member
BadlyDrawnBoy said:
So having the fan speed at a higher speed would help then? I only have it set to half. I'm definitely not upgrading to an 8", the smell is only apparent now that it is in the late flowering phase. I've had the 6" on a very low setting for the tent and it was plenty. Maybe I will keep upping the speed and hope it helps
Click to expand...
All 6" units are not the same. Cfm of your fan matters too. My 6" is 27" long and does a pretty good job with a 375cfm inline fan yet I believe it would do a better job with a stronger fan, maybe 700 cfm's. If your filter is shorter say 16" it is not going to need the same amount of cfm's to function. Find out what the appropriate cfm's are for your filter then match it to your fan speed.
 
Buba Blend

Buba Blend

Well-Known Member
BadlyDrawnBoy said:
So having the fan speed at a higher speed would help then? I only have it set to half. I'm definitely not upgrading to an 8", the smell is only apparent now that it is in the late flowering phase. I've had the 6" on a very low setting for the tent and it was plenty. Maybe I will keep upping the speed and hope it helps
Click to expand...
Just remembered something else. They have problems operating with humidity above 60%.
 
Observe & Report

Observe & Report

Well-Known Member
People telling you to turn up your fan don't have the slightest clue. There's a lot of variables but one of them is dwell time. The longer it takes the air to move through the carbon bed, the more is adsorbed. A larger bed (bigger filter) could help, as could better quality carbon. Also carefully check your ducting, if there is a leak inside the tent past the filter then you'll get stank outside. Maybe it wasn't a big enough leak before the plants were in full flower but now the leak rises above the threshold of detection. The fan itself can leak too, if my fan wasn't wrapped in plastic you could smell my grow but I have the fan/filter outside the grow and push through the filter.

If you're sensitive to smells, forget the Ona unless you want your house to stink like a urinal cake. I'm not sure who has that stuff going in their house and thinks it smells good.
 
Buba Blend

Buba Blend

Well-Known Member
Observe & Report said:
People telling you to turn up your fan don't have the slightest clue. There's a lot of variables but one of them is dwell time. The longer it takes the air to move through the carbon bed, the more is adsorbed. A larger bed (bigger filter) could help, as could better quality carbon. Also carefully check your ducting, if there is a leak inside the tent past the filter then you'll get stank outside. Maybe it wasn't a big enough leak before the plants were in full flower but now the leak rises above the threshold of detection. The fan itself can leak too, if my fan wasn't wrapped in plastic you could smell my grow but I have the fan/filter outside the grow and push through the filter.

If you're sensitive to smells, forget the Ona unless you want your house to stink like a urinal cake. I'm not sure who has that stuff going in their house and thinks it smells good.
Click to expand...
You push air through your carbon filter, I thought it was better to pull air through the filter.
Your fan leaks if it is not wrapped in plastic? That's the 1st time I heard that, is it a common problem with inline fans?.
 
Observe & Report

Observe & Report

Well-Known Member
Buba Blend said:
You push air through your carbon filter, I thought it was better to pull air through the filter.
Your fan leaks if it is not wrapped in plastic? That's the 1st time I heard that, is it a common problem with inline fans?.
Click to expand...
Generally, you can push or pull, the carbon doesn't care. The fans we use aren't designed to be leak proof. I run a stealth cab and can't tolerate any smell leakage, and I also like loud strains, so my fan has to be wrapped in plastic. I'm using an S&P TD-120 or whatever the base model is.
 
Jaybodankly

Jaybodankly

Well-Known Member
Go to Low Depo's and head over to cleaning supplies. They have these thing that look like night lites. Except they are full of fragrant oil. $5. Plug it in and wait a few moments. Some have a dial to increase oil rate.
 
Lucky Luke

Lucky Luke

Well-Known Member
I'm in a 4 x4, in mid to late flower, run a small, cheap 6inch Carbon filter and an 8 inch extraction fan. No smell. I did have some smell and doing the following fixed it for me.

Tape up around the duct fittings to make sure they are not leaking.
Turn the fan up for some (or more) negative pressure. You may not have neg pressue (or not enough) in the tent and your fans are causing the inside air to come out somewhere.
A 6 inch extraction fan would need to be run fairly hard to work well in a 4 x 4 and create good neg air pressure. Turn it to full on.

Yes, dwell time is important but the extraction fan normally needs to be pretty powerful or on high for that to matter.
 
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TCH

TCH

Well-Known Member
what Luke said is what I have found by reading a lot on the subject. if you are not pulling enough air out of the tent, the odor can leak out through other places such as zippers, intakes, etc... While you need to have a big enough carbon filter for your fan, you also need to pull enough air that the exhaust is the only place that air is leaving your tent.
 
chemphlegm

chemphlegm

Well-Known Member
BadlyDrawnBoy said:
I've got a 6" fan and 6" carbon filter inside a 4x4 tent. It's in late flower and I'm starting to smell it outside the tent, even though I'm using the carbon filter. I have the fan turned up half strength and the carbon filter is new, this is the first grow I'm using it with.

Is it typical to still smell a bit on the outside of the tent? It's odd because when i stick my face at the end of the duct exit from the fan, I smell no sign of cannabis. Yet when I open the door to the basement, I smell it immediately.

I was thinking of trying an additional odor control method. The ona brand sounds like it works, but I'm very sensitive to smells and I'm afraid it will be irritating to me. Synthetic smells are usually a no go for me.

The smell isn't a huge deal, I live in an isolated area and we rarely have visitors, and you only smell it if you open the basement door. But still...I'd just rather the filter did it's job and there was no smell. Odd because I smelled nothing up until a few days ago, then it got much stronger. I know the filter is working because no smell is noticed on the outer end of the exhaust. I turned the fan speed up a bit, thinking if it drew more air through the filter, it would be more effective. No noticed improvement yet.

Anyone else experience this despite having a carbon filter? I'm only growing 2 plants for medical use
Click to expand...
um, add more cans in and outside of the area for your greasy stinky fire!
 
stnr420

stnr420

Well-Known Member
BadlyDrawnBoy said:
I've got a 6" fan and 6" carbon filter inside a 4x4 tent. It's in late flower and I'm starting to smell it outside the tent, even though I'm using the carbon filter. I have the fan turned up half strength and the carbon filter is new, this is the first grow I'm using it with.

Is it typical to still smell a bit on the outside of the tent? It's odd because when i stick my face at the end of the duct exit from the fan, I smell no sign of cannabis. Yet when I open the door to the basement, I smell it immediately.

I was thinking of trying an additional odor control method. The ona brand sounds like it works, but I'm very sensitive to smells and I'm afraid it will be irritating to me. Synthetic smells are usually a no go for me.

The smell isn't a huge deal, I live in an isolated area and we rarely have visitors, and you only smell it if you open the basement door. But still...I'd just rather the filter did it's job and there was no smell. Odd because I smelled nothing up until a few days ago, then it got much stronger. I know the filter is working because no smell is noticed on the outer end of the exhaust. I turned the fan speed up a bit, thinking if it drew more air through the filter, it would be more effective. No noticed improvement yet.

Anyone else experience this despite having a carbon filter? I'm only growing 2 pl
TCH said:
what Luke said is what I have found by reading a lot on the subject. if you are not pulling enough air out of the tent, the odor can leak out through other places such as zippers, intakes, etc... While you need to have a big enough carbon filter for your fan, you also need to pull enough air that the exhaust is the only place that air is leaving your tent.
Click to expand...
BadlyDrawnBoy said:
I've got a 6" fan and 6" carbon filter inside a 4x4 tent. It's in late flower and I'm starting to smell it outside the tent, even though I'm using the carbon filter. I have the fan turned up half strength and the carbon filter is new, this is the first grow I'm using it with.

Is it typical to still smell a bit on the outside of the tent? It's odd because when i stick my face at the end of the duct exit from the fan, I smell no sign of cannabis. Yet when I open the door to the basement, I smell it immediately.

I was thinking of trying an additional odor control method. The ona brand sounds like it works, but I'm very sensitive to smells and I'm afraid it will be irritating to me. Synthetic smells are usually a no go for me.

The smell isn't a huge deal, I live in an isolated area and we rarely have visitors, and you only smell it if you open the basement door. But still...I'd just rather the filter did it's job and there was no smell. Odd because I smelled nothing up until a few days ago, then it got much stronger. I know the filter is working because no smell is noticed on the outer end of the exhaust. I turned the fan speed up a bit, thinking if it drew more air through the filter, it would be more effective. No noticed improvement yet.

Anyone else experience this despite having a carbon filter? I'm only growing 2 plants for medical use
Click to expand...
TCH said:
what Luke said is what I have found by reading a lot on the subject. if you are not pulling enough air out of the tent, the odor can leak out through other places such as zippers, intakes, etc... While you need to have a big enough carbon filter for your fan, you also need to pull enough air that the exhaust is the only place that air is leaving your tent.
Click to expand...
Ive found that the generic filters suck. Phresh filters are the best imo....if you are using a no name brand that could be the culprit
Click to expand...
 
Lordhooha

Lordhooha

Well-Known Member
Negative pressure. You always want the tent walls sucked in that's a good sign. My fans will pull my doors shut in my grow rooms never had an issue with smell
 
420Barista

420Barista

Well-Known Member
I have learned that the best way to mask the odors with a carbon filter is to blow the air through it.

If you have it hooked up to suck the air thru it it wont last as long.

when sucking the air thru a carbon filter the side of the filter closest to the outlet gets used up sooner than the end opposite the outlet, why because air will move in the path of least resistance so if its sucking, most of the air incoming say 75% is in the side nearest the outlet. and less input the further away from the outlet. and filtering like this will use up the carbon closest to the outlet sooner due to the airs path of least resistance.

when you have it setup to exhaust out thru the filter the whole filter gets used so untill all the carbon is used up the filter should mask the odors. and last longer over time
 
greg nr

greg nr

Well-Known Member
As long as there is negative pressure, I have no smells escaping my tent. If the fan goes off, even for a little while, I can smell it.

For times like cutting and curing when I have the tent open and lots of stank coming from my work table, I have a large carbon pack and filter sitting on the floor to act as a room scrubber. You usually can't smell anything in the rest of the house unless the whole house fan is on. No way to keep smells contained with a 40" fan blowing air out of the house.
 
Flagg420

Flagg420

Well-Known Member
420Barista said:
I have learned that the best way to mask the odors with a carbon filter is to blow the air through it.

If you have it hooked up to suck the air thru it it wont last as long.

when sucking the air thru a carbon filter the side of the filter closest to the outlet gets used up sooner than the end opposite the outlet, why because air will move in the path of least resistance so if its sucking, most of the air incoming say 75% is in the side nearest the outlet. and less input the further away from the outlet. and filtering like this will use up the carbon closest to the outlet sooner due to the airs path of least resistance.

when you have it setup to exhaust out thru the filter the whole filter gets used so untill all the carbon is used up the filter should mask the odors. and last longer over time
Click to expand...
This is why I buy iPower filters... the flanges are super easy to swap around after a bit, and then super easy to replace the carbon.... In the end I want 2 stacked on a fan as a scrubber, and a sealed room...
 
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