The BEST carbons for our use appear to be made from bituminous coal, rather than any woody product, like coconut shell, which is a gas phase carbon, rather than a liquid phase carbon. I'm sure "that OTHER" Boomer can 'splain the difference for us "kemistry challenged"...
Here are a couple of links on the difference between activated carbon and charcoal...(most pertain to air filtration, instead of water, but you'll get the idea)
http://jhs.pharm.or.jp/50(2)/50_148.pdf http://www.activated-carbon.com/solrec2.html http://www.abatement.com/residential...n_brochure.pdf http://www.ams.usda.gov/nop/National...atedCarbon.pdf