Most efficient gravity filter system – need market update

Wow, that's the first time seeing that Camelbak inline carbon element with the quick connects. That might be just the thing I'm looking for.

Instead of using the carbon inserts that they sell, does it look like you could somehow use granular carbon instead of having to keep buying the inserts?

Here is what I was putting together over the winter, mostly just for fun after following Ben Tang and Isaac's ideas about using chlorine bleach to treat water. I haven't actually done anything with this yet and I mostly use Aquamira drops now.

Clockwise from top left: marine charcoal from Petsmart, mesh charcoal bag from Petsmart, wide-mouth bladder (Nalgene Canteen), GSI Outdoors H2jO! Coffee Filter, a wide-mouth cap with an attachment point for a hose (the black one has a hole in the middle, the blue one has a short "elbow" tube coming out the top; you only need one).

Very basic: the charcoal goes in the mesh bag (just a 2d layer to keep the charcoal from leaking out) which goes into the H2jO which screws onto the bladder. I would treat water with chlorine bleach in a dirty bag which would flow down a hose into the clean canteen bag. The water would flow over and around the mesh bag and you could turn the canteen over and swish it around when the canteen is full. This system would also allow a lot of contact time with the charcoal. When not needed, I remove the H2jO and allow it to air-dry a little before storing it in a zip-loc bag. You then need another wide-mouth lid for the canteen.

Again, I don't think this would be necessary, except following chemical treatment, particularly chlorine bleach or maybe iodine (if that's even used anymore). It's my understanding that the charcoal has a beneficial use with chlorine, potentially removing harmful by-products of the chlorine.

Edit: er, the pic is sideways. Just turn your head.