Basement grow tent smell issue

Have a 5x5x7 tent in flower in the corner of my basement.2 600w led lights .I have a carbon filter on the outside of the tent on the ground filtering air pulling from the top hole of the tent.The bottom screen is open to take in fresh air.My basement is all open it is partial finished no rooms , very clean.I am having a problem with smell.I understand my setup may not be ideal and I need to make a few adjustments....I'm not taking In any fresh air besides what is being pulled from around my large basement...I've had a problem w.my last few runs at the end of flower as far as smell.I open the basement and it's like hitting a brick wall of dank.Once I get down the stairs its not as noticeable...almost as if the smell along with the warm air is rising and just sitting at the doorway.??? What recommendations or suggestions do you have.? I need help I'd like to correct this the right way so I can get back to my grow and not worry about the smell and blowing my cover.I do not want to exhaust outside however I can run a duct with a fan from outside for fresh air.Just not sure what I need to do for a permanent fix...Thanks
 

coreywebster

Well-Known Member
A few things to think about.

If there is a tiny gaps in the filter it wont work well.
If there is any gaps in the duct to fan to filter connection it will blow air out instead of through filter.
If your RH is too high the filter wont work well..
If your filter is picking up 95% of the smell and your recirculating air then that 5% that isn't getting cleaned is going to mount up.


The best thing to do is to vent the room properly, suck through your filter and get that air out of the house or at least out of the room so that new air comes in and the cycle repeats.

Don't use cheap filters.

Use a dehumidifier in the room if its needed. Right now as your running your humidity will rise and the smell will get slowly worse.
 

hellmutt bones

Well-Known Member
When that happens its usually my filter. Also like coreywebster said its probably issues with gaps between the ducking and your filter. So its a combination of both.
 

BostonBuds

Well-Known Member
That's a decent size tent. What size fan, what size carbon filter, how old is the carbon filter? You mention this is an ongoing issue, may be not the right equipment to start with.
 
I have a dehumidifier running in the basement.The tent is in the corner.I realize it's a large area to be taking humidity out of.The weather where I'm at is typical northeast so it is humid now.I would like to resolve this so I can run year round.I have a 400cfm fan along with a 400 cfm carbon filter.I have the fan on the lower setting so I'm not pushing air through it to fast.I replaced this filter once before because I had a smell problem.I wasnt sure if it was a leak, the filter, the ducting or what.So I replaced filter and ducting work.It did help but the my smell problem come back.So I'm thinking it is something else causing this.Possibly the humidity ? Possibly not getting fresh air from outside?I'd prefer not to vent outside the house...
 
A few things to think about.

If there is a tiny gaps in the filter it wont work well.
If there is any gaps in the duct to fan to filter connection it will blow air out instead of through filter.
If your RH is too high the filter wont work well..
If your filter is picking up 95% of the smell and your recirculating air then that 5% that isn't getting cleaned is going to mount up.


The best thing to do is to vent the room properly, suck through your filter and get that air out of the house or at least out of the room so that new air comes in and the cycle repeats.

Don't use cheap filters.

Use a dehumidifier in the room if its needed. Right now as your running your humidity will rise and the smell will get slowly worse.
  1. Thanks for the reply! I have a400 cfm fan and carbon filter ...to small you think? Or just could it be the humidity making it not filter proper? If I took fresh air in to the tent from outside ran like an inline fan with ducting from outside into the tent with fresh air would that help?
 
That's a decent size tent. What size fan, what size carbon filter, how old is the carbon filter? You mention this is an ongoing issue, may be not the right equipment to start with.
400cfm carbon filter and 400cfm fan. Filter was used for half a run previously but I mean who knows it may be no good if my humidity was high and screwing it up? Maybe not the right size for my setup ? Also I know recirculating air is killing me too...what options do I have here ? Without just dumping the exhaust air outside of my house ?Do I need an inline fan from outside for fresh air?
 

xFACEMANx

Well-Known Member
Money can fix almost nothing. Lol duh. But let's think outside YOUR box.
If I had the money and your problem.... I would treat the out side of my tent more like a sealed room. Like run a big filter and fan combo right in the basement. If it moves enough air it will clean the air inside the basement and keep,it there.
This of coarse should be in addition to the tents ventilation.
In reality, when running stealth you have to expect the extra cost, especially if you do it right.
You tent should have an in and an out.vent with fan for BOTH,and a carbon filter.
When running stealth the closer you can get the minimal cfm up to 2x the better off you are. This falls under redundancy for system 2 failing. You can still move a mass amount of air.
System 2 for you would be the big ass filter fan combo style used in a sealed room.
The smaller the room you get that setup in ,the smaller this fan combo will be.

This scrubs any left over odors in the basement leaked by system 1.
This is as good as you could get for your stusation that I can think of for now.
All this said. Get at least system #1 and make sure you listen to the others and don't fight yourself..... seal, seal ,seal.
 
Money can fix almost nothing. Lol duh. But let's think outside YOUR box.
If I had the money and your problem.... I would treat the out side of my tent more like a sealed room. Like run a big filter and fan combo right in the basement. If it moves enough air it will clean the air inside the basement and keep,it there.
This of coarse should be in addition to the tents ventilation.
In reality, when running stealth you have to expect the extra cost, especially if you do it right.
You tent should have an in and an out.vent with fan for BOTH,and a carbon filter.
When running stealth the closer you can get the minimal cfm up to 2x the better off you are. This falls under redundancy for system 2 failing. You can still move a mass amount of air.
System 2 for you would be the big ass filter fan combo style used in a sealed room.
The smaller the room you get that setup in ,the smaller this fan combo will be.

This scrubs any left over odors in the basement leaked by system 1.
This is as good as you could get for your stusation that I can think of for now.
All this said. Get at least system #1 and make sure you listen to the others and don't fight yourself..... seal, seal ,seal.
So 2 systems is a recommendation. I understand...makes sense I may do that..I may also try a larger filter.I did not.know I need fan for both the in and out vent.I just have the mesh screen on the bottom open and the carbon filter pulling from the top vent.Thought pulling air into the filter from the top would force air to be taken in through the bottom mesh screen.I currently have no inline fans going in or out all I have is the fan inside the tent for air movement and the carbon filter.
 

BostonBuds

Well-Known Member
400cfm carbon filter and 400cfm fan. Filter was used for half a run previously but I mean who knows it may be no good if my humidity was high and screwing it up? Maybe not the right size for my setup ? Also I know recirculating air is killing me too...what options do I have here ? Without just dumping the exhaust air outside of my house ?Do I need an inline fan from outside for fresh air?
If the tent is closed up and sealed 400cfm should be good for 5x5. Try closing up the vent you have opened, see if the tent walls suck in basically checking how strong your setup is pulling. I just have a passive intake like you, just a hole in the door, and if i hold a piece of paper up to it it gets sucked in from the suction.
 

growingforfun

Well-Known Member
It's not very effective at all to push through a carbon filter.


The only time I'd ever push through one is if I'm pulling through one already and I put a second one on the end for a double filter, but even in that case a inline carbon filter is better imo.

Your losing more air through the ducting than you think before it ever hits the filter, those things are full of pinholes.

Also... when your in a closed system like that I would ALWAYS have the filter in the tent being pulled through, PLUS have secondary filtration for the room. For example a filter with fan mounted on top just scrubbing the room.


In my setup I have a filter exhausting my room, a filter scrubbing my room, a filter in the area outside my room AND a ozone generator for near harvest spikes of smell.

Carbon filters and fan combos are relatively cheap, ~$200 for peace of mind is very cheap. And coming into winter I plan to upgrade my system AGAIN and for every 8 inch fan run a 8 inch splitter to 2x 8 inch duct connected to a 8 inch carbon filter each.

If you cant tell I'm a fanatic.

Edit- I also recommend insulated ducting as it cuts down on leaks a ton
 

xFACEMANx

Well-Known Member
It's not very effective at all to push through a carbon filter.


The only time I'd ever push through one is if I'm pulling through one already and I put a second one on the end for a double filter, but even in that case a inline carbon filter is better imo.

Your losing more air through the ducting than you think before it ever hits the filter, those things are full of pinholes.

Also... when your in a closed system like that I would ALWAYS have the filter in the tent being pulled through, PLUS have secondary filtration for the room. For example a filter with fan mounted on top just scrubbing the room.


In my setup I have a filter exhausting my room, a filter scrubbing my room, a filter in the area outside my room AND a ozone generator for near harvest spikes of smell.

Carbon filters and fan combos are relatively cheap, ~$200 for peace of mind is very cheap. And coming into winter I plan to upgrade my system AGAIN and for every 8 inch fan run a 8 inch splitter to 2x 8 inch duct connected to a 8 inch carbon filter each.

If you cant tell I'm a fanatic.

Edit- I also recommend insulated ducting as it cuts down on leaks a ton
Yes passive is a choice, but not a recommendation.if that's all your situation dictates then by all means just grow! Hell yeah.
But a controlled in and out of circulation is a must for adequate, and more inportantly,even air flow moving.
Remember that his situation is stealth here. You can move more air quietly with bigger fans on low settings with less power.
A speed control on fhe input fan is a must again..at least. Preferably both fans...but why?
I started with passive intake. Carbon filter in the growroom of coarse. Outlet fan pulled through filter and out..
The better your fan. The faster you stitching/seams on your growroom give.
If Tent.not sucking in like a junkie on a crack pipe you need a better fan. Speedcontrol can limit this to a point., but eventually your below cfm to adequately remove smell.
So now we add the intake fan and switch the speed control to this fan....or the tent blows up like a balloon because of the drag filter is causing. This is the worst case scenario. All air is pushed out without filtering.
Best case scenario, speed control on intake and outtake fans.
We can now go as fast or slow as we want during the grow to accommodate the cycle or temps. Slow it down in veg cuz it's not to smelly. Turn them up at flower if you smell anything..
Always have just a little negative pressure in the room. Tent SLIGHTLY PULLED IN.
Notes on second filter. If your room is matched right to your filter and ducting.( 6' at least)...there's info everywhere.... then you won't need one.
I've had police and fire in my house when we had an ailing grandma. They were across the hall from my tent....it wasn't legal then. We had a slotted door to make it worse. I could hear the fan. But no smell.
Buttt if your a freak about it and have the money the second filter is good for when one of the tent ones go out...redundency.also buy a spare fan for this day.
If you do go with a second filter....I wouldn't put it in the area with a filter. I'd use it to catch what the other one missed...outside the room where you don't want smell. You can setup room somewhat wrong with little leaks by accident, but that filter in the tent won't catch the smell that the tent leaked....third filter? lol I digress.

I'm a certified hvac tech. This was my bread and butter. But I'm always learning. Any other ideas?
 

growingforfun

Well-Known Member
Yes passive is a choice, but not a recommendation.if that's all your situation dictates then by all means just grow! Hell yeah.
But a controlled in and out of circulation is a must for adequate, and more inportantly,even air flow moving.
Remember that his situation is stealth here. You can move more air quietly with bigger fans on low settings with less power.
A speed control on fhe input fan is a must again..at least. Preferably both fans...but why?
I started with passive intake. Carbon filter in the growroom of coarse. Outlet fan pulled through filter and out..
The better your fan. The faster you stitching/seams on your growroom give.
If Tent.not sucking in like a junkie on a crack pipe you need a better fan. Speedcontrol can limit this to a point., but eventually your below cfm to adequately remove smell.
So now we add the intake fan and switch the speed control to this fan....or the tent blows up like a balloon because of the drag filter is causing. This is the worst case scenario. All air is pushed out without filtering.
Best case scenario, speed control on intake and outtake fans.
We can now go as fast or slow as we want during the grow to accommodate the cycle or temps. Slow it down in veg cuz it's not to smelly. Turn them up at flower if you smell anything..
Always have just a little negative pressure in the room. Tent SLIGHTLY PULLED IN.
Notes on second filter. If your room is matched right to your filter and ducting.( 6' at least)...there's info everywhere.... then you won't need one.
I've had police and fire in my house when we had an ailing grandma. They were across the hall from my tent....it wasn't legal then. We had a slotted door to make it worse. I could hear the fan. But no smell.
Buttt if your a freak about it and have the money the second filter is good for when one of the tent ones go out...redundency.also buy a spare fan for this day.
If you do go with a second filter....I wouldn't put it in the area with a filter. I'd use it to catch what the other one missed...outside the room where you don't want smell. You can setup room somewhat wrong with little leaks by accident, but that filter in the tent won't catch the smell that the tent leaked....third filter? lol I digress.

I'm a certified hvac tech. This was my bread and butter. But I'm always learning. Any other ideas?
Why did you quote me? It feels like your disagreeing with things I didnt say...

I never told him to oversize his exhaust. I told him to put the filter before his fan, this is proven to work better.
Then I advised a second fan/filter to scrub the room. This is extremely common practice around here and common advice. The scrubbing filter doesnt need to be massive.

I then just told him what I do, so he knew I wasnt just going to the extreme for no reason.
Stealth is extremely important to me, even with all my fans going nothing sounds like a grow room, because all my exhaust it plugged into my hvac, it just sounds like a normal house. My house has to be perfect because I have people over a lot and it's important to me nobody knows. My area is also a fair bit bigger than his so that's why I choose to many filters and plan on adding more, as you probably know, the slower air is pulled through the filter, the more effective it is, so that's the reason to split and add a second filter per fan.
Insulated ducting also helps cut down most of the noise.

I was just addressing ways to fully remove the smell, if he has questions how to reduce noise i have a ton of solutions to that as well
 

hellmutt bones

Well-Known Member
I have a dehumidifier running in the basement.The tent is in the corner.I realize it's a large area to be taking humidity out of.The weather where I'm at is typical northeast so it is humid now.I would like to resolve this so I can run year round.I have a 400cfm fan along with a 400 cfm carbon filter.I have the fan on the lower setting so I'm not pushing air through it to fast.I replaced this filter once before because I had a smell problem.I wasnt sure if it was a leak, the filter, the ducting or what.So I replaced filter and ducting work.It did help but the my smell problem come back.So I'm thinking it is something else causing this.Possibly the humidity ? Possibly not getting fresh air from outside?I'd prefer not to vent outside the house...

So you have it on the lowest setting..Bingo. go full because it should suck in the tent creating negative pressure. Try this and report back. You can tank me later noob bongsmilie
 
So you have it on the lowest setting..Bingo. go full because it should suck in the tent creating negative pressure. Try this and report back. You can tank me later noob bongsmilie
Lol yes sir.I had it on the highest setting and it was going to fast...almost as if the air being pushed through was going to fast and not being scrubbed properly.And yes my tent does suck in it does have negative pressure
 

xFACEMANx

Well-Known Member
Why did you quote me? It feels like your disagreeing with things I didnt say...

I never told him to oversize his exhaust. I told him to put the filter before his fan, this is proven to work better.
Then I advised a second fan/filter to scrub the room. This is extremely common practice around here and common advice. The scrubbing filter doesnt need to be massive.

I then just told him what I do, so he knew I wasnt just going to the extreme for no reason.
Stealth is extremely important to me, even with all my fans going nothing sounds like a grow room, because all my exhaust it plugged into my hvac, it just sounds like a normal house. My house has to be perfect because I have people over a lot and it's important to me nobody knows. My area is also a fair bit bigger than his so that's why I choose to many filters and plan on adding more, as you probably know, the slower air is pulled through the filter, the more effective it is, so that's the reason to split and add a second filter per fan.
Insulated ducting also helps cut down most of the noise.

I was just addressing ways to fully remove the smell, if he has questions how to reduce noise i have a ton of solutions to that as well
Why did you quote me? It feels like your disagreeing with things I didnt say...

I never told him to oversize his exhaust. I told him to put the filter before his fan, this is proven to work better.
Then I advised a second fan/filter to scrub the room. This is extremely common practice around here and common advice. The scrubbing filter doesnt need to be massive.

I then just told him what I do, so he knew I wasnt just going to the extreme for no reason.
Stealth is extremely important to me, even with all my fans going nothing sounds like a grow room, because all my exhaust it plugged into my hvac, it just sounds like a normal house. My house has to be perfect because I have people over a lot and it's important to me nobody knows. My area is also a fair bit bigger than his so that's why I choose to many filters and plan on adding more, as you probably know, the slower air is pulled through the filter, the more effective it is, so that's the reason to split and add a second filter per fan.
Insulated ducting also helps cut down most of the noise.

I was just addressing ways to fully remove the smell, if he has questions how to reduce noise i have a ton of solutions to that as well
No bud....I quoted you because you had some good ideas and I wanted to expand on them a little and how I do them.
I wouldn't tell you how to do your situation at all. Sorry if I sounded like that in anyway.
That's my biggest gripe with help on here is trying to sell your setup to a guy who can't use it, and is asking how to do his.
Your are gold bro. Sounds like you have it hammered down, and I wouldn't tell you different.
the second scrubber in the tent is a good idea regardless. It would be a hell of a lot smaller than an external.
But if I had the money and the ability,I'd do the external.....and if I'm a super freak about it all. The third one to the inside of the tent.
Just adding options my friend, I often ask myself what my growroom would look like if it was creative mode in Minecraft lol. No budget......geeezzzz.
Anyway sorry if you felt judged. Not what I meant at all. I liked your ideas.
 
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