I know the WATER threads are too many, but..

Snopes is run by a husband and wife team only, and often they are wrong.

The Wiki article answers one question for me: why not use glass bottles for purifying the water?
" * Bottle material: Some glass or PVC materials may prevent ultraviolet light from reaching the water. Commercially available bottles made of PET are recommended. The handling is much more convenient in the case of PET bottles. Polycarbonate blocks all UVA and UVB rays, and therefore should not be used."

It also addressed another question...leaching from the plastic:
* Leaching of bottle material: There has been some concern over the question whether plastic drinking containers can release chemicals or toxic components into water, a process possibly accelerated by heat. The Swiss Federal Laboratories for Materials Testing and Research have examined the diffusion of adipates and phthalates (DEHA and DEHP) from new and reused PET-bottles in the water during solar exposure. The levels of concentrations found in the water after a solar exposure of 17 hours in 60°C water were far below WHO guidelines for drinking water and in the same magnitude as the concentrations of phthalate and adipate generally found in high quality tap water.
Concerns about the general use of PET-bottles were also expressed after a report published by researchers from the University of Heidelberg on antimony being released from PET-bottles for soft drinks and mineral water stored over several months in supermarkets. However, the antimony concentrations found in the bottles are orders of magnitude below WHO and national guidelines for antimony concentrations in drinking water. Furthermore, SODIS water is not stored over such extended periods in the bottles."

(QUOTE) "I know the WATER threads are too many, but.. "

Actually, I think that we don't discuss water ENOUGH !!! It is widely acknowledged as the #1 survival need,(mostly, that is) yet, threads on this subject are dwarfed by guns-N-ammo threads.
I started with a $65 MSR ceramic-pump filter from Sportsmansguide,then got a Katadyn Camp Filter, and finally bit the bullet and got a Big Berkey ( which we now use daily filtering county water). I got two extra black filters when I bought it, but have since gotten several extra ceramic filters, because I'm trying to prepare to make filters for un-prepped family from 5-gallon buckets, if necessary.
Remeber,folks,NOTHING is as critical as water !! If you can't swing the bucks for the whole Berkey shebang, you can get a pair of 7" ceramic filters from Berkey Guy for under $60, delivered !!! ( He's a forum member )These come with the necessary washer and nut, and along with a plastic bucket, you can build a top quality unit that will filter several thousand gallons.
As easy and cheap as this is, there is no excuse for leaving this base uncovered.:thumb:

Not really worried so much about the polymers, although more on that later. Most plastic containers are not resistant enough to the sun's heat on a really hot sunny day to provide for adequate SODIS, in my opinion. No real scientific data on it, just know how little energy it takes for one of those to melt and/or burn, and how much energy it takes to kill some bacteria and viruses.

As for the polymers, there aren't so much for disposable water bottle containers, I guess, as from non-disposable plastic containers. While all of these items have been approved by the FDA, I am not entirely sure I can trust their judgement. In fact, a study in Europe last year found that repeated usage of disposable water bottles has the ability to leach endocrine disruptors (labeled in report as functional estrogens). Although if it were all I had, I still would use the disposable myself until something better came along. For using SODIS, it is my opinion that the best vessel to use is clear glass to make sure the uv has the proper intensity to disinfect. Plus, we always have a couple extras of those around.: You know, with the wife canning and all.:

The turbidity issue can be cleared somewhat with filtering, but another option may be to provide time for particulate matter to settle and decant the pre-disinfected water to another vessel. Some of the local water supplies are less than adequate, and I have seen water that could not be seen through when from the spigot, but after approximately 4 hours, had developed a turbidity level of 5 NTU. Still not visually the hottest, but after proper filtering, the level can be taken down to less than one NTU, where it should be aesthetically pleasing.

It must be noted that some turbidity may come from algal growth....SODIS may actually excacerbate this. I would just try to steer clear of surface water with a possiblity of algal blooms when using this method of disinfection.

EPA rethinks plastic bottle component's safety aspects

Nonetheless, health officials suggested a number of things people could do to limit their exposure to BPA, like throwing away scratched or worn bottles or cups made with BPA (it can leak from the scratches), not putting very hot liquids into cups or bottles with BPA and checking the labels on containers to make sure they are microwave safe. The drug agency also recommended that mothers breastfeed their infants for at least 12 months; liquid formula contains traces of BPA.

BPA has been used since the 1960s to make hard plastic bottles, sippy cups for toddlers and the linings of food and beverage cans, including the cans used to hold infant formula and soda. Until recently it was used in baby bottles, but major manufacturers are now making bottles without it. Plastic items containing BPA are generally marked with the number 7 on the bottom for recycling purposes.

http://www.cleveland.com/nation/index.ssf/2010/01/epa_rethinks_plastic_bottle_co.html

I too don't think there are enough threads on water. It's something everyone needs and most in this country take for granted. I guess working for a municipal water company I'm rather biased.

There's more to making water potable then just killing bacteria and viruses. And the idea of drinking water with a turbidity of 30 isn't something I look forward to. The river we draw from to make potable water usually has a turbidity of 2-3 NTU. You can see the bottom of the river @~ 6 feet but that's far from the Federal standard of .3NTU. The water we process typically runs ~.03NTU and there's still a chance of Chrypto and Giardia being present.

And running a sand filter without the process steps of coagulation/ flocculation, and sedimentation will not make clean water. I've seen it here when the chemical feeder here craps out. Turbidity increases are sure to follow and a rapid sand filter won't do much of anything. Water leaving the filter won't be much, if any, cleaner.

There are several proven steps that need to be followed if there is any hope of producing potable water.
http://en.wikipedia.org/wiki/Water_purification
Coagulation/ flocculation
sedimentation
filtration
disinfection

I don't know enough about ceramic filters or the Berkey black filters to give any idea as to how well these work or for how long. I do know that they are a much finer filter then sand so they should catch more things. But they would also clog more frequently, just the nature of the beast. Backwashing would clean out some things, though the surface scrubbing would only get some of it off. What gets inside might not get washed out completely.

I also don't know enough about plastics but most things these days are sold in them. I assume they're kinda safe, though not as safe as glass.(never heard of clear, lead free, glass leaching anything. Colored glass maybe.) I do know that the sun does have an effect on many plastics, yet not so much for glass.

Biocidal silver

I'm thinking colloidal silver might be worth looking into, being that NASA has been using it in space craft for years....

In the 1960s, NASA’s Manned Space Center (now known
as Johnson Space Center) and the Garrett Corporation,
Air Research Division, conducted a research program to
develop a small, lightweight water purifier for the Apollo
spacecraft that would require minimal power and would
not need to be monitored around-the-clock by astronauts
in orbit. The 9-ounce purifier, slightly larger than
a cigarette pack and completely chlorine-free, dispensed
silver ions into the spacecraft’s water supply to successfully
kill off bacteria. A NASA Technical Brief released around
the time of the research reported that the silver ions did not
“impart an unpleasant taste to the water.”

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20050031218_2005019673.pdf