For Platypus gravity filtration accessories:
http://www.platypushydration.com/accessories.aspSweetwater inline silt stopper:
http://www.campmor.com/webapp/wcs/stores...productId=13620Seychelle inline filter:
http://www.backpackinglight.com/cgi-bin/backpackinglight/seychelle_in_line_filter.htmlYou're going to have to do some fancy footwork to make a non-collapsible pop bottle work in a gravity feed system.
Bear
_________________________
No fire, no steel.