I know you didn't ask but...
I have spent a lot of time camping and hiking... next year I will have my 25-year veteran award for Boy Scouts, I just finished a 5-1/2 year stint as scoutmaster after having done about every other job in the scout troop and cub pack for all of my adult life. So I've also used "a lot" of water filtering and "purification" methods and I continually educate myself on the best methods; I have to teach it to the new scouts and teach it for Camping and Hiking merit badges.
1. Boiling kills everything - crypto, bacteria, viruses. Actually, lower temperatures will work given enough time but bringing it to a "rolling boil" (a defined temperature) works - no need to boil for "5 minutes" even at high elevation. It just wastes fuel.
2. Chlorine and Iodine treatments have a hard time with Crypto, bacteria- no problem, viruses - so so.
2a. Because of good water treatment plants in the USA, water-bourne viruses aren't a big deal in most of US and Canada.
2b. Chemical contamination is more of an issue (fertilizers and industrial chemicals).
3. A sub micron filter does a pretty good job a getting rid of crypto
... hence for years I used a PUR pump filter (it may have been a Hiker model) to get the cryptosporidium and backed it up with water treatment tablets when in the back woods.
MOST of the filter technology over the past few decades did a good job at crypto and other "big" stuff, but still could allow bacteria. The "ceramic" type filters have a hard time with the smallest bacteria. (Berkey included - Berkey used to advertise a 0.9 micron "absolute" rating but stopped and just goes with a 99.99whatever% rating now instead of advertizing a 0.2whatever micron "nominal" rating like many people do. Also only the Black Berkey with the 99.99whatever% rating is a purifier and relies on the black anti-microbial coating, not filtering, to kill the bacteria -- it might be silver, I don't know.
5. People don't like the taste of chemical treatment and would prefer a filter if possible.
5a. A 50mg vitamin C tablet crushed in iodine treated water removes the bad taste (AFTER treatment).
5b. An activated charcoal filter gets rid of chlorine taste.
6. A ceramic or membrane filter element will be damaged by freezing... in the winter, leave them home and boil your water.
There is a new hollow fiber membrane filter technology available in the last couple years that makes chemical treatment unnecessary. (Originally used for dialysis machines)
7. The Sawyer PointONE filter is one of the filters (there are a few other brands) that use this new type of filter. It filters out ALL types of bacteria, even the really small stuff. It has a 0.1 micron "absolute" rating.
8. For the international traveler and for peace of mind, Sawyer also has Point ZeroTWO which will also mechanically filter VIRUSES and is rated as a water purification system. (0.02 micron absolute rating) They have a kit to make a bucket filter from either PointONE or PointZeroTWO filters.
Now I don't carry chemicals with me anymore. YAY!!!
They have one type for backpacking, one for buckets, faucet adapters, even an 10" inline type.
https://sawyer.com/international/products/And they last a really really really long time. (They are cleaned by backflushing, so they continue to flow like new.)
They don't do much for the bad taste of the city water (algae taste yes - gets rid of that, chlorine taste no), so on safe tap water I continue to use my Berkey Sport Bottle (which I NEVER rely on for water safety, only for taste) since it makes the nasty city water in and around Indy taste like water instead of a combination of the bottom of a creek and a swimming pool.
I am a water snob I guess you could say, the water here at work is filtered and UV treated, and it still tastes like a creek/pool.
10. Finally, I still like to use a carbon/charcoal filter for chemicals and improving the taste (like the Berkey Sport Bottle, or an inline filter at home).
by tkayinnc » Wed Apr 30, 2014 12:03 pm 
