I'm finalizing my water purification plans for a post-crisis world (which seems to be getting very near). I'm going with a creamic water filter similar to the one that Potters for Peace has developed for use in Third World countries. I have the material and equipment to make and fire the clay vessel. My water source is a spring-fed woodland stream that runs about 100' from my house. Its flow rate is 30 gal/min, and it has never run dry in the 33 years that I've owned the land, even in years of drought. Here's why I've come to you good folks: Does anyone here have 1st-hand knowledge of these filters? The PFP model is coated or impregnated with colloidal silver to kill pathogens. My concern is about the cost/availability of the colloidal silver in a post-SHTF world. Why wouldn't a drop or two of clorine bleach in the filtered water work just as well? TIA for any help or info!