Light weight Water Purification?

. HERE are peoples thoughts so far

I have a 2oz pump water filter that was UK military issue in pilot survival packs. It takes about 5 minutes to process 2 liters into a clear platypus bag which I then lash to the top of my pack if the sun is out. That makes it 4um filtered and UV treated. Warm enough to cook with in the evening with minimal fuel and cool enough to drink by the following morning. :)

One of the biggest weight savings you can make is to ELIMINATE carried water. This does not help with that. A battery operated device that weighs less than 4oz and purifies a half liter of water in 45 secs will give good results. mUV, Steripen, and perhaps others I am not familiar with, have achieved this. In many areas (not deserts, of course,) you can simply walk from stream to stream, drinking or camping without carrying more than a couple ounces more (in container weight.) A half liter weighs about a pound. So, it is easily possible to drop ALL carried water and replace this with a 5min break at a stream. In a pinch, an empty Beef Jerky bag or gallon zip-lock(ala Ryan Jordan) will work. Soo, by dropping the water, and carrying a Steripen and used Gatoraid bottle, you can save a LOT of weight. A typical hiker usually carries two liters (about 2kg) of water weight. This is replaced by 0, in many areas or less than 500g (half liter,) if you are a little more paranoid. A savings of 1.5kg or about 3-1/3 pounds.

Yeah, carrying 0.5 liter is all I ever do.  In areas where I know I’ll cross a stream sometime in the middle of the day.

If it’s cold, 0.5 liter is all I need all day if I start hydrated and get a big drink at the end of the day.