DIY Carbon Filter


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This is my DIY carbon filter that will go into my 1'x1'x2' grow cabinet.












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cheers, logged into memory banks.
Can`t believe I bought the carbon filter I currently use.

I know !! outrageous
DIY is the best fun


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And here is my (almost) complete micro grow setup. Need to make it lightproof and we're ready to go.

So, what do you guys think?




Inside "usable" space is 1'×1'x1'11". Have 4x23w CFL bulbs inside, heat protection of lights "chamber" at 100F, adjustable intake fan and wired-in timer for lights.

Do you think it can produce me any bud?


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Cheers Caconym!
Still testing the box. A bit of a struggle to control temps inside. I have ambient temps between 80 to 85 F, which makes inside temp fluctuate between 85 and 90 F. So I presume that I will only be able to start a grow and a journal in mid September, when it cools down a bit.


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I've struggled this summer as the temperature in the room my box is in hit nearly 85f. It's a case of moving as much air as possible through the box really.

You might do a little better with the filter mounted under the glass so it would be pulling air directly out of the grow space and sealing the lights off and running an additional unfiltered exhaust fan for the heat from the lights.

LED lights typically run cooler than CFLs for the same light output so you might save a few degrees by switching. A single 40w COB would light a 1x1 really well.


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Well I mounted the filter as high as possible to save as much vertical space as possible. I have tried running the box without the glass and temps were way hotter. My guess that is due to fluids flowing in the path with least resistance and so my front two CFL's are left with no cooling.
I may look into LED's but not in nearest future... I want to start my first grow ASAP


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I found the thread finally !
Ok, so I can see you've used mesh for the outer wall, but what have you used in the Centre ? Also, what is the white plastic piece called ? I take it it's some sort of plumbing section.


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I used pencil cup for inside, and the white plastic stuff is ventilation ducting reducer/adapter. But you can go creative about it. I spent around 4 hours in hardware store before it "clicked" :)


Member of the Month: May 2009, Oct 2010, Sept 2017
Thanks. I used activated carbon sifted to particle size of 4mm so they would stay inside the mesh wire

I realize you did this out of necessity, so the carbon wouldn't pass through your rabbit wire. But the smaller the particle size, the better a carbon filter will work. Ergo, the larger the particle size, the less capable the filter becomes. It's a surface area thing (I think).

Might not be an issue with such a small box. But if it becomes one, try redoing your filter with smaller media.

OtOH, a carbon filter that is made up of densely-packed tiny particles would require something stronger than the average computer fan in order to actually push an adequate amount of air through the restriction.

Speaking of fans...

I'd have cut the intake hole much lower in the box (or on the bottom, and set the box on some sort of legs) - and skipped an intake fan, instead just using a decent exhaust fan, and relying on it to pull air through your box. Aside from the efficiency of the thing, it'd have created a negative air pressure situation, ensuring that any "stinky air" only exited through the filter.

You do get extra points (IMHO) for deciding to orient those CFL bulbs horizontally like that! I often see such things set at all kinds of angles, which mainly just leaves bright spots on nearby walls (instead of on the plant(s), lol). Ordinarily, I'd recommend creating reflectors out of soda pop cans or the like, but if that box is only a couple feet tall, I'm guessing the top is serving decently as a reflector.

If that is good clear glass, it's probably attenuating your lights about 9%. If some kind of plastic, the figure could be higher.

Do you think it can produce me any bud?

Sure, in theory.

Are you going to cut a hole in the bottom of your box so that you can set it on top of a pot - or are you intending that space for the plant and its pot? Regardless, I recommend you go with some kind of 100% indica (or near as makes no difference). Just for sh!ts and giggles, I left a Jack Herer clone in a 6-ounce styrofoam coffee cup to see how tall it'd get. I killed it at (IIRC) 42", lol. So there's only so much one can do with root restriction (IOW, small pots). Or maybe one of the midget auto-flowering strains, such as Crop King Seeds' Dwarf Low Flyer; I have no experience with this strain, and am just going off its description which states it'll stay under 2' tall. There are undoubtedly other strains that stay small.

I hope you start a grow journal. We have had relatively few micro-grows (and even fewer successful ones, most having been abandoned). That'd be a way for you to get ongoing help from the community - and, potentially, to help others.

I've seen a few threads that might help you with strain selection (et cetera). One was a group Solo cup grow. The other was, too, but used those little 1.5-ounce ones.

Good luck!


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Cheers TorturedSoul!

Ofcourse I did it out of necesity, i only have a pc fan available, as anything larger couldn't be called stealth :)
But there are three things, particle size, air pressure and thicknes of the filtering layers. So if one thickens the filtering layer one can go with larger particle size and keep same filtering properties. I was testing my filter with incense until I was getting only a hint of the aroma. I presume it'll work just fine and if not, I can tweak it a bit.
The box is at negative pressure as I have set up a wired in potentiometer for adjusting intake fan speed. Used my anemometer to check airflow speeds and volumes being taken in and pulled out.
The intake fan is at that height because I use it as a fan to blow on my plant, so no need to blow on the pot, which will basically take all that space below the fan :)
I have started a grow journal, you can check my profile, I only started this thread and the one called Katins's first bagseed micro grow - soil and CFL's
Check it out if you're interested :)


Member of the Month: May 2009, Oct 2010, Sept 2017
I was testing my filter with incense until I was getting only a hint of the aroma. I presume it'll work just fine and if not, I can tweak it a bit.

Best incense I ever had stank up an entire room. OtOH, I once came home to find neighbors out trying to figure where that skunk was that was stinking up the entire neighborhood, lol. In other words, the difference was an exponential one. (But I did have more than one small plant.)

I have started a grow journal, you can check my profile, I only started this thread and the one called Katins's first bagseed micro grow - soil and CFL's

Might want to visit your User CP and create .SIG(nature), and add a link to your grow journal to it, so that it's there at the bottom of all your posts. That can spread the awareness of it (as/when you end up posting in other threads).


Using you and your project as inspiration, I made one too, not as neat as yours but should do the trick ! Well, that's if my small desk fan is powerful enough to push the air through. Here's some pictures

Thanks for all your inspiration !!

What does inside look like? Same at tape it ?


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Member of the Month: May 2009, Oct 2010, Sept 2017
Sweet build on the box and the filter , can’t wait to see the grow journal for this .

The member's .SIG at the bottom of es posts lists several journal threads, including this one (which is currently ongoing) :
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