On this first link he uses both a carbon filter (insulation) and activated carbon granules. http://forums.mycotopia.net/cannabis/8038-diy-carbon-scrubber.html on the second link every1's already saw there is just a carbon filter. http://www.gardenscure.com/420/security/60127-ryoko-builds-diy-activated-carbon-filter.html IS this Refill of CTC rating of 70% activated carbon more potent than the pet activated carbon at the pet store . link for ctc 70% activated carbon - http://www.hidhut.com/catalog/refill-activated-carbon-30-lbs-70ctc-p-107.html Anyone used a Odorsok filter before? www.odorsok.com ? (it looks like a carbon scrubber or is it just like a filter you put inside a carbon scrubber?