doesnt matter if its at the bottom or top only the direction of flow. as long as it pulls air OUT of the space you want scrubbed and thru the filter. thats how he has it set up from what i can see.
Mal420xl Reviewed by Mal420xl on . DIY: Carbon Air Filter - CHEAP, and EFFECTIVE! Security is important to marijuana growers, and odors can lead the police or unwanted neighbors straight to your grow room. There are a number of 'odor solutions' out there, but they can be quite costly. Here is a simple method you can use to build your own carbon filter. It will take you about half an hour to construct it, and it will cost $20 to $30 dollars. And it is completely safe. Aside from its main advantage of being ultra cheap, this method is also very versatile. It utilizes the Rating: 5