Does A Carbon Filter Remove 100% Smell

UPDATE, after a couple of days the odor has returned in the new filter. It's harder to detect because the new filter is like 3X the size and I also think the stink builds over time.

So I take back what I said about Phresh filters. They are fine.

I also take back what I said about 100% odor removal. Yes the carbon gets rid of the weed odor but in my experience produces its own subtle odor. So I have an odor that fills the closet and part of the room I wouldn't have if I wasn't growing Cannabis.

I have no idea what is causing the odor. It's not from the carbon per se, since I ran the unused filter as a scrubber and stuck my nose in it and only detected a very faint acrid smell (probably the acid used to activate the carbon.) Just a guess that the plant stank is fermenting in the filter and some of those products are getting past the carbon. That's why it smells the way it does, a bit like drunk breath to me, hard to describe.

Observe & Report said:

UPDATE, after a couple of days the odor has returned in the new filter. It's harder to detect because the new filter is like 3X the size and I also think the stink builds over time.

So I take back what I said about Phresh filters. They are fine.

I also take back what I said about 100% odor removal. Yes the carbon gets rid of the weed odor but in my experience produces its own subtle odor. So I have an odor that fills the closet and part of the room I wouldn't have if I wasn't growing Cannabis.

I have no idea what is causing the odor. It's not from the carbon per se, since I ran the unused filter as a scrubber and stuck my nose in it and only detected a very faint acrid smell (probably the acid used to activate the carbon.) Just a guess that the plant stank is fermenting in the filter and some of those products are getting past the carbon. That's why it smells the way it does, a bit like drunk breath to me, hard to describe.

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Im not sure what to tell you man, theres something ive never heard of there and ive used carbon in industrial sized cleanups for odor for well over a decade. Its true carbon wont scrub every molecule but its normally ones like carbon monoxide because its already a carbon based molecule. Anything carbon wont scrub shouldnt be coming from your plants. Something in your grow must be offgassing a specific thing but im not sure what gas it would be from a grow. I would be able to tell you exactly what with air testing equipment but im stumped what it could be coming from your grow.

Maybe youve got different additives youre using that are combining for a chemical reaction that you dont know about? Same idea as the ammonia and bleach chemical reaction that everyone is aware of. Youve got something wierd going on there tho man and its not normal.

I recently purchased a Can 66 for my 3x3 and after installing it , left rhe condo for 15 minutes and when I cam back the smell was gone. I haven't smelled anything since. It's awesome.

Chef420 said:

I recently purchased a Can 66 for my 3x3 and after installing it , left rhe condo for 15 minutes and when I cam back the smell was gone. I haven't smelled anything since. It's awesome.

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Yep thats what it normally is. Observe and report is an exception to the rule and hes got somehting very unusual going on there.

I've been growing a year and up until this point at week 6 my crappy filter that came with my kit would be overwhelmed. I believe the fan was paired incorrectly with it. That's a consideration.

Chef420 said:

I've been growing a year and up until this point at week 6 my crappy filter that came with my kit would be overwhelmed. I believe the fan was paired incorrectly with it. That's a consideration.

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Thats not what he's describing tho, hes saying its not the smell of his plants getting thru the filter. Certain gases carbon wont absorb, carbon monoxide, methane, theres plenty of them and most of them are not friendly ones. None of them should be coming out of a grow room and if i was him id make the effort to try and figure out what it is. Its likely an unintended chemical reaction happening between two products he's using.

Bet I could do that sewer job without the mask. My sense of smell packed up and left with my hair.
I appreciate you sharing your expertise.

Have you seen these?

ANC said:

Bet I could do that sewer job without the mask. My sense of smell packed up and left with my hair.
I appreciate you sharing your expertise.

Have you seen these?

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Anything thats aquarium grade carbon is good. Thats just a filter they made for the fish tank. If youre gonna do a DIY thing youre better off just buying the bulk aquarium carbon like this
https://www.walmart.ca/en/ip/aqua-tech-activated-carbon-filter/6000187907526
cause then you can make it into anything you want. A can filter for negative air, a portable air scrubber, whatever you want. Thats a filter they made from the raw carbon, that will be more expensive and less versitile in my opinion. Anything carbon is generally effective for odors.

As far as being able to do a sewage remediation without a filter why would you want to? Im not the grunt labor shovelling it up, im the guy who does the air testing to make sure the structure is actually safe to live in when those guys are done. Besides why would you want to smell shit all day long if you didnt have to?

I thought it might be useful to make an extra layer of wrapping, it's pretty cheap.
Would one 3' 8" filter be enough for a 15 x15 area?

Lol, I can barely smell shit, gave me real advance in the diaper stage with my daughter.

Observe & Report said:

UPDATE, after a couple of days the odor has returned in the new filter. It's harder to detect because the new filter is like 3X the size and I also think the stink builds over time.

So I take back what I said about Phresh filters. They are fine.

I also take back what I said about 100% odor removal. Yes the carbon gets rid of the weed odor but in my experience produces its own subtle odor. So I have an odor that fills the closet and part of the room I wouldn't have if I wasn't growing Cannabis.

I have no idea what is causing the odor. It's not from the carbon per se, since I ran the unused filter as a scrubber and stuck my nose in it and only detected a very faint acrid smell (probably the acid used to activate the carbon.) Just a guess that the plant stank is fermenting in the filter and some of those products are getting past the carbon. That's why it smells the way it does, a bit like drunk breath to me, hard to describe.

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Do you push air through or pull air through your filter?

coreywebster said:

Do you push air through or pull air through your filter?

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We always do it so the filter is before the fan, but thats more just to stop the machine itself from being contaminated. I never really thought about it to be honest but i cant see it really making a difference. Id do it the same way in a grow just cause if you somehow end up with spores or something in your fan that would suck. You'd keep contaminating your grow from your fan.

ANC said:

I thought it might be useful to make an extra layer of wrapping, it's pretty cheap.
Would one 3' 8" filter be enough for a 15 x15 area?

Lol, I can barely smell shit, gave me real advance in the diaper stage with my daughter.

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Wouldnt hurt, really as long as you arent bottlenecking your cfm airflow theres no such thing as too much carbon. You just have to change out the filter/carbon less often. As far as if its adequate or not, id guess no, but unless something has a rated CFM youre just guessing.

Been looking at the can33 and can66 filters, they specify a CFM range, or ranges rather, depending on if you just want to recycle or are exhausting elsewhere.

ANC said:

Been looking at the can33 and can66 filters, they specify a CFM range, or ranges rather, depending on if you just want to recycle or are exhausting elsewhere.

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Honestly thats something i just never thought about. The industrial sized machines we use its not like you can just change where the filter goes. On ours it sucks the air thru the filter. This is what they look like.
http://www.atlanticdesigninc.com/wp-content/uploads/negAirPhotos1-483x288.jpg
that white thing is the prefilter then under it you slide in whatever filter youre using, HEPA, carbon ect.

Any DIY stuff ive ever done i always put the filter before the fan. Why contaminate the fan if you dont have to?


EDIT -----------------------------------------------------------------------------------------------------------------Sorry i completely misread what you said there. sigh, happens sometimes. dyslexic.

Initially i thought you meant should your fan be sucking air thru the filter or pushing it thru. obviously on a second read over which i always do i realized i read it completely wrong.

Lets try that again

By recycle they mean what is described as an air scrubber. One that exhausts is a negative air machine. They are essential indenticle except the neg air machine has an exhaust hose you are supposed to vent outside where the air scrubber doesnt it its output just recirculates (or recycles) around the room. A neg air setup is always gonna need a stronger fan because it has to force the air all the way out and suck air back into what is likely a sealed room. This creates much more resistance. Using the same exact can filter you'd need a fan rated for much more, id guess 30-40% more or higher.

haze010 said:

We always do it so the filter is before the fan, but thats more just to stop the machine itself from being contaminated. I never really thought about it to be honest but i cant see it really making a difference. Id do it the same way in a grow just cause if you somehow end up with spores or something in your fan that would suck. You'd keep contaminating your grow from your fan.

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The reason I asked was just because pushing air through the filter would mean it had passed through the ducting then exited the filter. Some ducting is a cheap copy, the acoustic stuff has a membrane inside, with the cheap copy it doesn't, which results in bacteria inside the ducting which can smell of anything from rotten fish to stale beer.

Just a thought really. I have never had any kind of smell once air has been filtered but I know shitty ducting can create some weird smells

coreywebster said:

The reason I asked was just because pushing air through the filter would mean it had passed through the ducting then exited the filter. Some ducting is a cheap copy, the acoustic stuff has a membrane inside, with the cheap copy it doesn't, which results in bacteria inside the ducting which can smell of anything from rotten fish to stale beer.

Just a thought really. I have never had any kind of smell once air has been filtered but I know shitty ducting can create some weird smells

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I go cheap but regularly replace it. I do that with alot of things though. I tend to heavy clean everything that can and replace what cant fairly regularly. Im sure my costs are higher than many but i like things clean and neat.

the way we do things in remediations is the machine is first, and the first thing exsposed is the prefilter. then the Carbon if its being used, then hepa or whatever other filter is being used. the only thing ever going thru our machines should be clean air. thats how we do it.

thats what i meant by not contaminating the machine.

Activated carbon works pretty well for adsorption of most organics. There are quite a few gasses which it won't do much for though. Formaldehyde, hydrogen sulfide, acetic acid, flouride, and several other nasties. Even ethylene, which plants release small amounts of during photosynthesis.

Not sure of which manufacturers add potassium permanganate to their activated carbon filters, if any, but it is used to help scrub a broader range of gasses when used in conjunction with activated carbon. When it(KMnO4) reaches saturation it can produce a smell similar to what's been described. It's purplish in color, and will lighten up and start turning white throughout its life. I know of several industrial suppliers that combine it with activated carbon for general air treatment in process plants and refineries.

Something else I'd like to add, is that under no circumstances should you EVER put an ozone generator in or around any occupied area. That stuff will really screw you up; several hours in a sealed room with big one and you'll have chromosomal damage, if you can even still breathe without choking on blood. It also destroys activated carbon and releases carbon monoxide and other nasties upon contacting it in higher concentrations. Ozone is a heavy oxidizer as well. Run it through a fan and it's going to turn white and fall apart. I personally won't mess with it without an ozone specific ppm meter. I'm sure the remediation guy above has some experience with it; some companies fog flood/mold damaged homes with them but it's done in a controlled environment and no ones allowed in until it's completely evacuated. It's just too damn dangerous when it's concentrated. Granulated catalysts are available to destruct ozone, and can last several years in a filter similar in appearance and function to a carbon scrubber; but you'll be paying over $30 a pound for the stuff. It needs the air dried before entry as well. A large tungsten heating element is usually implemented upstream of the catalyst, dehumidifiers and regenerative dessicant systems fail quickly when concentrated ozone is ran through them.

It really bothers me when these rinky dink hydro outfits sell ozone generators without disclosing any of the hazards associated with them. I also advocate making your own scrubbers. Get some real granulated or cylindrical carbon and potassium permanganate designed for air treatment from a real supplier, not busters bud emporium or hanks fish food store. Buy a manometer, some stainless screen and ducting hardware and you'll quickly be able to create an appropriately sized scrubber to fit your air flow requirements that will far outlast and outperform the common lightweight junk that's for sale everywhere.

sonson176 said:

Not sure of which manufacturers add potassium permanganate to their activated carbon filters, if any, but it is used to help scrub a broader range of gasses when used in conjunction with activated carbon. When it(KMnO4) reaches saturation it can produce a smell similar to what's been described.

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I doubt Can or Phresh have KMnO4 added because they don't mention anything about it, I'm sure it's ordinary activated carbon. If they did have KMnO4 would it get saturated in a day or two, which is all it took for a new Can 33 to start emitting a slight smell?

Unless you've got the filter on top of a coal fired generating station, it would last quite a bit longer than 2 days. It's life is highly dependent on the amount of gasses, their molecular weight, and airflow. But in a situation such as yours it should outlast the activated carbon. I suspect your filter might contain reactivated carbon, which could certainly have been bought second hand from large industrial operations, and was previously combined with KMn04 or other additives before being sieved out and reactivated. Couple that with child labor reactivating carbon from god-knows-what in some third world country and funny smells should be anticipated. Don't trust marketing, especially on completely unregulated products.

It might be worthwhile to check out some other elements of your system as well. See if the smell is there without the filter in place if possible.

CAN and Phresh say they use virgin carbon. The filters don't have an odor when they are brand new.