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DIY High Flow Carbon Filter


New Member
You could build one with what ever materials you have. 6" pvc pipe would work, however in a 5 gal bucket application you would greatly reduce the amount of carbon the contaminated air would touch in a single pass, thus reducing the effectiveness of the filter. if you were to use it as a scrubber where the air would pass over the carbon multiple time, then this would not be a big issue. On the the other hand there is no law that says it has to be a 5gal bucket. You could theoretically use a number of containers ranging from a rubbermaid tote to a 55gal drum, just uses what ever you need to fit your needs. The building concept would be the same just modify the design a bit.
Yeah I was thinking of doubling it, Two buckets .. one on top of the other
Kinda just double the recipe lol:Hookah:


New Member
where does the fan go on this , i currently have a carbon filter and 4" fan inside my tent with a flexible line hooked to it and running out of my tent . does the filter you built go on the end of that flexible hose ? do i need a second fan before the filter you built ?


New Member
how big of a vent do you suggest with this filter? something pretty heavy duty otherwise it wont pull enough air?


Well-Known Member
SunGod I really do like your Filter / scrubber , I know it will be very effective !!

As it has about 4 inches of carbon

Those common longish hydroponic carbon filters used to use 2 inches of carbon now most are using just 1 inch

Like you I used the Pellets , I bought 25lbs of them from eBay for $50

Before I bought the Carbon I looked into it and found that the Carbon pellets work the best and last twice as long as other types.

I made this one last week from a mesh waste paper basket and a roll of wire with 25lbs of carbon pellets set 2 inches in thickness.

It has a 6 inch 12v 170CFM axial fan mounted in its top , I still need to get the pre filter


Active Member
Here a step by step filter construction that I am currently using. Prior to installing this filter you could smell my grow if you go within 25 feet of my house. Within 20 mins I couldn't detect the slightest odor unless you went in to the actual grow room... I have this filter set up a a single pass filter hooked up to my room exhaust. I have not noticed any temp rise or air flow reduction. I hope this will be beneficial to the 420 community. Enjoy

Materials needed
1 5 gal bucket w/ lid
4 gal of activated carbon pellets
3' section of 4" PVC drain pipe
1 roll of duct tape
1 section of flexible ducting
1 section of blue filter material
1 package of zip ties
1 4" pvc cap

Step 1

Drill holes in the sides of the bucket and PVC pipe. The more holes the better the air flow. (Note drill the bucket with a fast drill speed helps to keep the burrs down, and the PVC with a slow drill speed prevents the pipe from breaking.)

The end result should look like this you only want to drill holes in the pipe as high as you think the carbon will go you want the first hole in the pipe to be about 3"-4" submerged in carbon. If you drill to many holes simply cover the holes up with duct tape. You can use the PVC cap to plug the end of the pipe that will be in the bucket or just find something to plug the end. I used an empty sour cream container and silicone caulk.

Step 2

Place the end of the pipe on the center of the lid and trace with sharpie marker then cut out as carefully as possible with a razor knife. This is where the pipe will go through the lid you want a tight fit to prevent pipe from shifting in the carbon.

Step 3

You will need to cut the filter material to size and wrap the material around the pipe and the bucket, and secure it with zip ties. This will allow you to use larger holes for better air flow while keeping the carbon from falling through.

Step 4

Trim off excess zip ties

Step 5

Place the plugged end of the pipe in the bucket. Ensuring the pipe stays straight and centered pour carbon in filling the bucket around the pipe.

Step 6

Install lid and run a bead of silicone around the seam.

Step 7

Install the filter on you inline fan. if you have a 4" fan then it should be straight forward if you have another size you will need a PVC adapter to step up to your fan and ducting size. If you have any questions you can post so everyone can see and I will be happy to answer.
My version seems to work well,plus small enough not to get in the way,plus it pulls air threw carbon filter.i am terrible about posting,hope this goes thru,and maybe help someone



Active Member
This is my first attempt at doing anything like this,need medical for graves disease,and it's so dry here couldn't buy any to save my life,but tired of migraine headaches.would appreciate any help,about to try some auto flower.


Well-Known Member
I love the DIY aspect of growing and considering building my own carbon filter. I see this is an older thread, so my question is; how long can you use this style filter before it needs to be recharged? I'm tired of spending $100 on filters that you might get a year out of.


Member of the Month: May 2009, Oct 2010, Sept 2017
It would depend on the amount of carbon material, the quality of the carbon material (there are multiple grades)... and how tightly it was packed in. With a DIY approach, you have the opportunity to end up with whatever size/shape you can dream up and construct; threads like this one are just suggestions.

I'd think a long tube, tightly packed with small-sized high-quality carbon material might be a good design, but it would probably take a fan with more guts than the average exhaust setup - remember that many fans just aren't designed to move air against a restriction / pressure, and that their actual flow rates go way down under such conditions. Be worth thinking about if you have to replace your HVAC and decide to salvage the Dayton blower out of it, though, IMHO. Those things seem to function more or less properly for decades, often with no maintenance or even cleaning.
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