DIY High Flow Carbon Filter

Sungod

New 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.

Bucket_and_tube.jpg




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.

Lid.jpg





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.

Tube_with_filter.jpg



Step 4

Trim off excess zip ties

Zip_ties_trimmed.jpg


Bucket_with_filter_material.jpg




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.

Carbon_added.jpg


Carbon_added1.jpg




Step 6


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

lid_installed.jpg





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.
 
whats up great setup the one i wanna build is very similar but the only thing holding me back is i cant find cheap carbon pellets! where you get yours? how much if you dont mind me asking and how many pounds of carbon require to fill 4 gallons worth? thanks
 
Had to buy mine online at pondmerchants.com I paid 50 bucks for 15lbs including shipping. Seems like a lot but it isn't when comparing a commercial filter with comparable cfm capacity. Would love to find it cheaper though.
 
Had to buy mine online at pondmerchants.com I paid 50 bucks for 15lbs including shipping. Seems like a lot but it isn't when comparing a commercial filter with comparable cfm capacity. Would love to find it cheaper though.

Here ya go....Filter Carbon Pellets

52 pounds worth. $46.99. I'm in the green zone (Central). Cost me $11.00 to ship it. 57 bucks, tax, tag and title shipped to my door. 52 lbs. Little over a buck a pound. I could make 3 or 4 5 gallon bucket setups with 52 lbs...:peacetwo:

Evolution Of A GrowCab-From The School of hard Knocks
Grow Cab Ventilation Redesign-All About Heat
Deep Water Culture with Fogponic Contruction
 
Here ya go....Filter Carbon Pellets

52 pounds worth. $46.99. I'm in the green zone (Central). Cost me $11.00 to ship it. 57 bucks, tax, tag and title shipped to my door. 52 lbs. Little over a buck a pound. I could make 3 or 4 5 gallon bucket setups with 52 lbs...:peacetwo:

Evolution Of A GrowCab-From The School of hard Knocks
Grow Cab Ventilation Redesign-All About Heat
Deep Water Culture with Fogponic Contruction

Thanks for the input def the best price I've seen. +reps
 
Thanks for the input def the best price I've seen. +reps

I found activated charcoal local. Place called "The Pump Store". Pond and pool supply house. 25 lb bag, 25 bucks. I am building this thing tomorrow. I currectly have a prebuilt with a 4" inlet. With a turbine 170 cfm fan, it loads the motor bigtime. Also cuts cfm notably, and in turn the cab temps go up 3-4 deg when connected. I bet 25 lbs will last a while, and I bet there wont be hardly ANY backpressure. The only difference in my project will be reducing the 5 gallon bucket to a 3 or a 4 and place the completed filter assembly in a sealed Rubbermaid tub. I'll cut a 4" hole where the PVC pipe exits the Rubbermaid tub then on the other end I'll take a 6" galvanized starter in the other end of the Rubbermaid tub and connect my 6" flexible dryer vent hose to it where it is then exhausted through a louvered flap outside. I'll take photos of the project and post them. Too COol! Excellent thread!:grinjoint:
DSCF8410.JPG
 
Nice Thread. So do you have your fan just sucking air through the carbon and recirculating it into your room? Or is it vented somhow?

I do not have an air conditioner so I vent my room. My 435cfm fan pulls the room air through the filter then through the light and then pushes the air out the room. The filter cuts the odor down to undetectable levels with one pass.
 
I found activated charcoal local. Place called "The Pump Store". Pond and pool supply house. 25 lb bag, 25 bucks. I am building this thing tomorrow. I currectly have a prebuilt with a 4" inlet. With a turbine 170 cfm fan, it loads the motor bigtime. Also cuts cfm notably, and in turn the cab temps go up 3-4 deg when connected. I bet 25 lbs will last a while, and I bet there wont be hardly ANY backpressure. The only difference in my project will be reducing the 5 gallon bucket to a 3 or a 4 and place the completed filter assembly in a sealed Rubbermaid tub. I'll cut a 4" hole where the PVC pipe exits the Rubbermaid tub then on the other end I'll take a 6" galvanized starter in the other end of the Rubbermaid tub and connect my 6" flexible dryer vent hose to it where it is then exhausted through a louvered flap outside. I'll take photos of the project and post them. Too COol! Excellent thread!

Great grow cab very efficient use of space +reps. I can't wait to see your finished filter. I'm sure there is room for improvement. I think it will be good to watch the the design evolve and get better.
 
Great grow cab very efficient use of space +reps. I can't wait to see your finished filter. I'm sure there is room for improvement. I think it will be good to watch the the design evolve and get better.

Hey dude. Thought I'd check in with ya and give you a personal progress report. First, thanks for the design idea. This project wouldn't have came to fruition the way it did without you. I got it installed yesterday, and the second design was a winner for me. I COULD get by using the 170 cfm turbine fan and probably be ok, however, the other day I had my hydro gal order me a 6" inline turbine fan. CFM on it is around 450. I will go ahead and install it in place of the 4", run a 4-6 reducer into the carbon filter. I bet it will handle it with flying colors. The fan is controlled via a 5 amp reostat (ceiling fan controller). If I need to REDUCE the cfm, it should be a no-brainer. I am a little concerned about driving 450 cfm through the 4" pvc pipe. If memory serves me, isn't yours driven by a 6" turbine fan as well? If so, how much rpm you think your losing (cfm) when the carbon filter is connected? I know with my 170 cfm pushing through a factory Phresh 4", it reduces rpm and cfm substantially. With our home built unit, flow is substantially increased, and not a lick of odor, even with your nose right at the outlet. I just think maybe I'm pushing the envelope a little hard trying to ventilate the cab with the 170 cfm, ESPECIALLY when connected to a filter. RoorRip
 
Hey dude. Thought I'd check in with ya and give you a personal progress report. First, thanks for the design idea. This project wouldn't have came to fruition the way it did without you. I got it installed yesterday, and the second design was a winner for me. I COULD get by using the 170 cfm turbine fan and probably be ok, however, the other day I had my hydro gal order me a 6" inline turbine fan. CFM on it is around 450. I will go ahead and install it in place of the 4", run a 4-6 reducer into the carbon filter. I bet it will handle it with flying colors. The fan is controlled via a 5 amp reostat (ceiling fan controller). If I need to REDUCE the cfm, it should be a no-brainer. I am a little concerned about driving 450 cfm through the 4" pvc pipe. If memory serves me, isn't yours driven by a 6" turbine fan as well? If so, how much rpm you think your losing (cfm) when the carbon filter is connected? I know with my 170 cfm pushing through a factory Phresh 4", it reduces rpm and cfm substantially. With our home built unit, flow is substantially increased, and not a lick of odor, even with your nose right at the outlet. I just think maybe I'm pushing the envelope a little hard trying to ventilate the cab with the 170 cfm, ESPECIALLY when connected to a filter. RoorRip

I'm not sure you would lose any rpm's if your fan is pulling air through your filter. If you are pulling air then the air in the ducting between the filter and the fan will be less dense causing less resistance on the fan thus actually causing a higher rpm. Think about when you plug the sucking side of your vacuum the motor races until you unplug the hose.

The reason you put so many holes in the 4" pipe was to reduce the air restriction as much as possible. The goal was to not have anymore restriction than the existing 6" ducting. I think the design come pretty close especially with the big holes you put into your pipe and bucket.
 
I'm not sure you would lose any rpm's if your fan is pulling air through your filter. If you are pulling air then the air in the ducting between the filter and the fan will be less dense causing less resistance on the fan thus actually causing a higher rpm. Think about when you plug the sucking side of your vacuum the motor races until you unplug the hose.

The reason you put so many holes in the 4" pipe was to reduce the air restriction as much as possible. The goal was to not have anymore restriction than the existing 6" ducting. I think the design come pretty close especially with the big holes you put into your pipe and bucket.

I'm PULLING air passively from the cab and PUSHING into filter. The air that gets through the filter is then carried outside via 6"flex. Over the weekend, I added a cheap 6" 240 cfm inline fan that pulls from the filter box and pushes into the 6" flex carried outside. I agree if I had room, Id have located the filter in the cab and connect to the inlet of vortex fan, but I'm stuck having to PUSH through the filter. Also, what's your opinion on the 450 cfm 6" turbine fan replacing the 170 4" unit, reduced to 4" and into the filter assembly? You think our filters will flow the rated 450 of the 6" fan?
RoorRip
 
man thats nice do you have any pics of plants in there latter on so i can see how hood your turn outs were id really like to look how they have done over time
 
I found activated charcoal local. Place called "The Pump Store". Pond and pool supply house. 25 lb bag, 25 bucks. I am building this thing tomorrow. I currectly have a prebuilt with a 4" inlet. With a turbine 170 cfm fan, it loads the motor bigtime. Also cuts cfm notably, and in turn the cab temps go up 3-4 deg when connected. I bet 25 lbs will last a while, and I bet there wont be hardly ANY backpressure. The only difference in my project will be reducing the 5 gallon bucket to a 3 or a 4 and place the completed filter assembly in a sealed Rubbermaid tub. I'll cut a 4" hole where the PVC pipe exits the Rubbermaid tub then on the other end I'll take a 6" galvanized starter in the other end of the Rubbermaid tub and connect my 6" flexible dryer vent hose to it where it is then exhausted through a louvered flap outside. I'll take photos of the project and post them. Too COol! Excellent thread!:grinjoint:
man thats nice do you have any pics of plants in there latter on so i can see how hood your turn outs were id really like to look how they have done over time
 
Great post. Do you use it like a scrubber in the room or is the filter out side of the grow room?

You can use it both ways the room I originally used it in was vented so I just pulled the air through the filter and out in to the atmosphere. the exhaust was virtually odorless. The air flow through the filter was good, I noticed minimal temp rise with the filter attached. In a sealed room you could use it as a scrubber.

what is the blue filter materiel?

the filter material is just some bulk filter material I picked up at the local hardware store. comes in a big roll you just cut off however much you need. I've also seen it in different colors but it works great in a variety of applications. Just have to be creative.
 
Has anyone built one of these with 6 inch pvc?

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.
 
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