Theres a couple DIY carbon Scrubbers on here. I figure I could add my own design in the hopes that it will fit someone's application better than others, or inspire them to build their own, like I was. This application is suited for small grows (I only have 2 plants, grown under 130w of CFLs). I bought all parts from Home Depot and Petsmart. The total cost was less than 40 dollars, a small price to pay for security! First thing's first! Lets look at materials and prices: (HD=Home Depot)(PM=Petsmart)(HI=household item) Web Absorber Furnace/AC Carbon Filter x 1 (HD) $12 Adjustable 3 inch 90 Degree Ducting Elbow x 1 (HD) $4 5 feet of 6x24 19 guage chicken fence x 1 (HD) $7 1/2 Gallon of Activated Carbon For Fish Filters x1 (PM) $12 Panty Hose x 1 (HI) Duct tape x 1 (HI) Zip Ties x As many as you need (HI) So now that we have our material list, let's begin the build. As a note for my exhaust, I have a 3 inch PVC 90 degree street elbow attached to a 3 inch male adaptor with the threaded side going out my box. The adjustable furnace elbow fits PERFECTLY into the threaded end of the male adaptor. This is our filter, elbow, and fencing. Ignore the white things; they came with the filter but are ultimately useless for this application I cut 11 inches of the chicken fence and then cut it in half, so we have one feet of length instead of two feet. Once this is cut, wrap it around the elbow so you have the right size and shape and attach it to itself. This is MUCH harder than it sounds, but it is do-able. I used the wire that holds the fencing together to attach it to itself. To do this, take a 2 inch strip of the wire and thread it through some of the squares so it cant unravel. I did this on the top, middle and end of my cylinder. When you are finished, it will look something like this: Note how the 90 elbow fits into my exhaust. Our next step is to fit our outer filter. Now the carbon filter I use has a layer of activated carbon(black) and another layer of particle trapper(blue). I use both for extra protection. The filter comes with a black plastic webbing; get rid of it, because it serves no use. Now we take a pair of nice sharp scissors and cut the filter in half. It will fit the cut-in-half chicken wire cylinder perfectly for width Next, we roll up our chicken wire like you roll up a sleeping bag There will be some extra once it is rolled up. I overlap it a little bit, but I cut off the last 3 inches or so. That way there is enough, but not too much extra. Save this piece!! You never know when it might come in handy After you removed the extra, take two of your zip ties and attach them to each other so it reaches around enough. You may need to daisy chain more than 2 depending on the size of your zip ties Now, we roll up our "sleeping bag" again, and this time, attach the zip tie to the top of it, nice and snug Flip, and repeat Once this is done, cut off the extra zip tie that sticks out. get as close as you can to the zip housing so as to not create a sharp spot to snag the panty hose on. Let's bust out the panty hose now. The purpose of the panty hose is to prevent the carbon from spilling out the bottom of the scrubber while still allowing air to pass through. If you dont have any panty hose, you can buy them pretty much anywhere that sells socks for $.99 a pair. Remove a leg off of the hosiery, and pull it nice and tight on one side of the filter, like so. It should look like this on the bottom if done right: (Forgive me for the overexposure) It has now come time to fill this puppy with carbon We take this: And pour it into here: So it looks like this: I left about 2.5 inches on the top for the elbow, but once it is done, we will top it off anyway. Now I don't have pictures for the next few steps because I modified my design at this point after I had taken pictures, so I will do my best to explain this as best as possible to explain my next picture. Take the elbow and insert it into the filter, crimped side out. The crimped side is the one with the little ridges on it. Once you have done that, the fun part comes. Bust out the duct tape Take your tape, and duct tape THE SHIT out of the top where the elbow meets the filter. Use a lot, and start about 3 inches below the top edge of the filter so the tape holds the assembly together. You need a lot to support the weight of the filter. I also put a layer of tape around the top of the elbow(the crimped side) so it fits snugger. Once you get it taped, you should be able to hold the filter vertically by the elbow and it can hold itself up from the tape. Take your carbon and fill it up a bit more through the elbow so as to top it off. Once you do this, grab the other leg of the panty hose. This part is hard to explain without pictures, but I will do my best. Overlap the other panty hose, go just above the end zip tie and tie it off via however you can. After this, take the extra material of the first panty hose and pull it back over the second panty hose (still with me?). After number one has overlapped number 2 again, tie it off on the bottom via a simple knot, and cut off the extra. When you are finished with all that, you will get something like this: NOTE: I added another double zip tie in the center of the filter. This is recommended, but not needed. VIOLA!! Your brand new carbon filter is done. This slides right into my three inch male adaptor with a perfect fit. I have it made so that it slides right in and supports itself and hangs down, with nothing extra! ~*~FINAL STEP~*~ START ADDING THIS STUFF: I hope you enjoyed my guide. The build was inspired by other carbon filters in GC, and a love for the herb we call Marijuana If you have any questions, do not be afraid to ask!!!