Hello, I have been working on finishing my flowering cab and am almost done. I was really seeing if anyone had any good advice for me. Here is a sketchup of the cab. The shelf can be raised and lowered. I am mounting CFLs at the top on the back wall. I was considering adding 2 3" passive intakes on the bottom left and my 120mm 85cfm fan to the top right. I have all the materials to make the pencil holder carbon filter but am a little unsure how to keep the carbon or the inner container from falling out when I turn it side ways to mount it to the fan. I am open for any and all suggestions. I dont want to start cutting and then get some great advice on how I should finish setting it up. Thanks.