The OfficeMax ones are the same as Wolfman's original ones from Walmart on page 1. I'm using two: one each for two sets of four 80mm PC fans. I don't have a grow yet, since I'm still in the build phase, but I tried it out by putting fresh cinnamon toast inside, and I couldn't smell a thing from outside the cab. A lot depends on how you secure it to your ventilation system; if any air has a path around the carbon, you're not going to get the full effect. Also, you want to make sure your carbon isn't in too large of chunks; crush it down a bit if it is. Not powder, but not pellets, if that makes sense.
I've never had the need for a stealth grow before, so it's always been shit everywhere, but I'm working on a stealth DWC CFL cabinet with nothing visible from the outside except for the holes in the back for ventilation. I owe the last couple of years of bud to the late great Overgrow, and I always told myself I'd give back when the time was right, and this place has the same vibe as OG, which I lurked incessantly (trying not to be so inactive since this will be my first hydro grow, and I'll probably need all the help I can get). I'm trying to help with little shit I'm finding out from my build, until I get a digital camera and start my grow and journal.
I put 2 pieces of cut to fit filter screen on the bottom and filled with carbon, another 4" circle of screen, more carbon, etc... untill the can was filled. I used 2lbs of carbon to fill it. My question is will a 90 CFM booster fan be able to pull enough air through the can where it has a 4" opening on each end but nothing on the sides? will I have to drill/machine holes/slots in the can? I would assume I would use more of my carbon with out the holes/slots as air will have to travrel the entire 10" length of the can. Sorry if I confused anyone I'm typing fast before I head out to work.