How often should one replace their carbon filter?

[Mr. Bongjangles]

I'd like to gauge the general opinion on how often one should refill or replace their carbon filter.

Most manufacturers say 1.5-2 years, but I've yet to have one last that long when used for flowering plants.

I run about the recommended 200cfm through my can33, but it only makes it a year in my 1k/5x5 tent before noticeable smell begins to make it through.

So yea, I'm going with 1 year, but I'd like to see where the rest of icmag is at on this one.

Thanks in advance for input!

 

[fully baked]

I have a smaller carbon filter that I replaced for the first time after 4 rounds or so of flowering. I started to notice some extra smells seeping out and figured it was about time.

I'm curious to hear what everyone else says too.

 

[Haps]

The nose knows, when you can smell flowers, it is time. It is a year for me too, I could go a couple extra months, but it is easy to do between crops.
H

 

[BobbleheadJed]

I don't believe time is the most important part of the equation of the filter life of carbon. The weight of the carbon, the amount of VOCs and odors introduced to the carbon, the type of carbon, and the air flow are all part of the equation. Engineers get paid a lot of money to calculate those equations I'd bet. I'm not an engineer, but I know filters a bit.

Haps has it about right. The nose knows, unless you are an engineer.

I run a Can-33 also with about the same 200 cfm through the filter as you Mr. Bo., a little less as its on a variable. I can safely say it will make it through 4 flowering cycles under conditions I might subject it to with no problem.

So I'm going with 15 months, somewhere between a year and a year and a half. Depends on how stinky your nugs are.

 

[kaljukajakas]

About 3-4 crops for me too with a 16" long 4" ID, 7" OD DIY filter full of dense carbon in a 400W cabinet with a 130 cfm fan.


I've recently added a 2W ionizer to the cabinet to see if it makes a difference. The small amounts of ozone neutralize quite a bit of the smell in the cabinet but theoretically the ozone should also neutralize some of the odor molecules that have been caught in the filter, thus prolonging it's life. Basically continuous chemical regeneration of the activated carbon. I'm just 1 grow into it though so it will take time to see if there's a difference...

 

[NorthernKronic]

Ive run both a can33 and a can66 they both last about a year for me. It depends on the genetics your running and just how smelly they are...

The nose knows.... I would go no more than 12 months tho..

-N.Kron

 

[xcrispi]

Varies greatly here ,
Alot longer w/o doing hydro . 16 mos.
Carbon gets saturated faster w/ hydro because of the increased humidity . 8-9 mos.
Crispi

 

[sunnydog]

I suspect the carbon being coated with airborn filth probably has a-lot to do with the life of the carbon.
If it's coated with crap, it can't absorb,right?
So, next filter I run, I a going to augment the existing filter material with some good 3m filter material from H-D.

SD

P.S. probably should have had a "when it starts to stink" option on poll, LOL.

 

[Retardo Motabon]

I'd say 9-12 months. By the time you smell it, others can too! The longest I've gone was 14 months (and that was plain dumb)! My humidity ranges from low 30's to upper 40%. I oversize the filter for my space greatly and after a year its a gamble still.
RM

 

[Kinderfeld]

1 year give or take.

 

[killabrown420]

i got the 6" fan filter combo from HTG, and unfortunately it hasn't been able to make it one flowering period. I do grow ebb and flow, so maybe the added humidity is the culprit, or maybe it's b/c it's not a high dollar one. I do grow some seriously stinky stuff, and maybe if I toned down the fan with a speed controller I could fine tune it, but right now I'm thinking I should just buy a bigger filter, or build my own and order carbon in bulk off ebay.

Anyone use a combination of filter and something else to catch the leaks?

 

[BeeBee]

I always use an over-sized filter, because I can--my cabinet is a 10 foot by 13 foot bedroom. I make my own pre-filter, from 1.5 inch thick polyester quilt batting, and wrap the filter AFTER I mount it. I remove the pre-filter and wash or replace it every six months.
The exhaust is blowing out through a roof vent, so a little smell is OK; the first filter lasted 3 years. It was a Mountain Air. The second filter, a GH Dutch Breeze, is 2.5 years old.