My $3 Carbon Filter

aww man that sucks.

Alright I uploaded the pics of the final setup in place... and fixed link in my sig so just follow it, dont wanna post em here

Your local pet shop has whats called a filter bag made for the very carbon you're using, cost me $1. It's a draw string, and used in large aquarium filters. Water flows freely through it, and so will air. Awesome thread...

Normally you can find those bags in MANY sizes also... thats a good point Michael. Wont have to sew anything, they have draw strings on them (well most, some are just open at top).

I have seen these bags sell for as little as $1 and upto $10 but $10 are BIG bags, like 12x24

Mine is 4X12, and is sealed inside of ductwork, air has to flow through the carbon to work, so seal with aluminum tape, every crack sealed helps. I placed a carbon prefilter behind it, and fit it all in by shaving the fins that direct the air, and putting them back in. $20, and it works.

Using a vent is a great idea.... I am about to do another diy filter to filter air into my attic, i think I will use the vent idea for in the attic side to place a carbon filter in to freshen the air going in there and outside.

Thanks!

I did this with a filter bag and charcoal in front of fan or pulling thru the bag, and putting the bag in the exhaust vent. I had to stuff 2 bags in the exhaust to fill it. In both cases I had limited air flow and not good odor control.

I used around 4 oz. of charcoal per bag as I remember. The bags were around 1.5 inches thick at the thickest point. I gave up and got a regular filter, which I can refill after I drill out the rivets.

I have a small 3x3 tent with just 2 plants, ill be exhausting out a second story window. Do you think this will be enough so people outside wont smell it? I'd love to save the 80$ on a carbonfilter + there way to big for my small grow

panhead said:

Here is a way to make carbon filters for less than $3 each,they take about 30 minutes to make & all components & materials can be bought at any meijers store.

Materials needed.

1 4 pack Scotch Brite cloth towels from Meijers............$2

1 Bottle Activated Carbon from Meijers or fish store......$6

1 sewing needle & thread from Meijers........................$2

Total cost for 4 carbon filters...................................$10.

First you start out with the Scotch Brite cloth,its very thin & extremely strong,i find it much stronger than aluminum window screen material,its next to mpossible to tear yet the weave of the material is such that it will not restrict air flow.

Take the Scotch Brite & fold it in half or to a smaller size to fit your needs,like this.

Then take & sew 3 & 1/2 sides of the Scotch Brite closed making a pillow case looking thing,make sure to leave a few inches open to fill the "pillow case",then pour in the Activated Carbod to a little less than half way full & sew up the spot that was left open to pour the carbon in.

Here is the carbon.

Here are 2 finished Carbon Filters.

As for attaching them to what you need to there are several options,there is always duct tape in a pinch but i connect mine using hose clamps from the hardware store,the hose clamps make it easy to take the filter off if needed & is more secure that tape.

These work every bit as good as a $80 carbon filter i bought off of ebay & cost less than $3 each & about 2 hours time to make 4 of them,its not getting any cheaper than that.

Click to expand...

Dude....I cannot begin to thank you enough....My neighbors thank you and my wallet thanks you!!

great idea
+rep for you man, i will try it
peace

Is it ok to use nylex mesh instead of aluminium?

This is a fantastic idea! I really dont have the $80-100 to spend on a premade can filter and it would be a downright pain in the ass to hang up in a grow thats already running.

Im headed to the store tomorrow get the materials needed and tape a filter down to both sides of my exhaust fan to make sure it gets scrubbed twice. Ill double check all of my seals for the venting flaps to make sure no smell can get out.

Excellent guide! +Rep to OP

Following up with the results from my application from this method

Its a double edged sword, unless youre prepared with the right equipment. I use 2x 240CFM 6" intake and exhaust for my 4x8x6.5 hut, 208cuft. Without either a larger / higher capacity exhaust or a fan speed controller, you are going to have very high positive pressure which puts both the fans and the plants under strain. Not all fans work with fan speed controllers. I was glad I had amazon prime and overnighted a fan speed controller by hydrofarm. Lucky for me, my inline fans didnt have a power relay and its hard wired in to a grounded plug. Now that Im running my intake at ~60-70%, pressure seems stable.

Material cost from meijer was actually about $29 and they didnt have scotch brite cloths like that. Ive seen these types of cloths before used on food service equipment, they are actually more effective than actual linen and hand towels for light-medium cleaning purposes. I went to walmart and they had clorox handiwipes which are the same thing, different brand and color for an additional $3. It wasnt so bad to do, Ive done some stitching before. If you get thinner thread like I did, make sure you knot the ends really well or it will be pulling out of your eye quite a bit.

Reccomend securing finished filter on the outside of the duct rather than inside for better airflow and suction and less chance for catastrophic damage. The idea of a bag of black pellets going through my fan does not sound very appealing. It could potentiall break the fan, make a huge mess, and even start a fire. There has been SOME smell still in the air, I think it is residual from the length of time that its been unfiltered.

Total Cost: $32 for materials + $25 for duct controller = $57
Total Time from creation to installation: 2.5 hours. I wasnt medicated at all until after installation

Bottom line: If you have the time, necessary equipment, and the basic sewing skills to rig this filter up, go for it. These WILL work in a tight money pinch. The carbon filters with rated CFM speeds are a lot friendlier to use, and not all that much more expensive. They look a lot better, and are a lot safer to use too. Your best bet is to plan the cost of a filter thats pre-built into your budget if you are going to stealth grow.

how much odor will it get rid of and will it work like the 100 ones

So i was gonna try this, i have pc fans in my grow box tho. And although there are circular holes cut out around the fans where i could put sum ducting, im putting the box flush against the wall & dont want to. So i was wondering if these filters would be effective if I just duck taped them over the holes (without adding ducts)

Panhead this idea rocks! thanks from a fellow michigander

Form and function, and cheap to make. Excellent work.

very nice gonna have to give it a try...

I was going to use one of these 6" engine intake air filters, only $25 shipped on ebay, put a nylon inside, fill it with carbon, tie the end of the nylon and attach it to the inline fan, I would think you would get more life and be able to remove more odor out of this method and the only thing you would have to replace is the carbon, do you think the OP's idea would work better?

genius!!!! why didnt i think of that, i have like 3 full cold air intakes just lyin around!! nice find