Bill,<br>I would rank the water purification options:<br><br>1 Boil<br>2 Potable Aqua<br>3 Iodine, Kahn-Vassher or tincture<br>4 Chlorine tablets<br>5 KMnO4<br><br>I might take some of the Potable Aqua instructions and make these general as I think they apply to all chemical options.<br><br>Strain cloudy water prior to any treatment option.<br>Shake container to disinfect cap threads for the chemical options.<br>Increase (double?) wait time for very cold water.<br><br>Even though I do not carry bleach, or Iodine tincture I like having basic instructions like these available with the PSK. It is likely that I would use these in an local emergency situation. <br><br>I do carry Iodine crystals (Kahn-Vassher method, Polar Pure) in my car kit which has good instructions on the bottle (also excellent shelf stability and will treat may gallons of water). I also carry a mechanical filter system (Katadyne), again with good instructions.<br><br>I would rank the mechanical filter 1st or 2nd in the list of options if we were not considering PSK sized options.<br><br>As for a color chart for KMnO4 dilution, I agree nothing seems to be very helpful. I found reference to a 1mg/L solution for water disinfection, with no supporting efficacy information. I think we all may be left to our own devices as to what is pink, rose, or purple. <br><br>Again, thanks for putting together this Great Cheat Sheet. <br><br>Randy