water purification

There are lots of pollutants in the water that iodine won't cure. It will disinfect (you hope) but will not remove toxins, heavy metals, fecal matter, etc. that is present especially in the large cities. In Delhi the shower water was sticky, and salty. The plastic you generate during your 4 month trip is incredibly insignificant compared to what is generated by the local population every day, so don't worry about it, and look after your own safety first.

if you are going to do this then take a trekking water filter with you. this will remove larger particals. iodine can bond to particals in unfiltered water and produce some unpleasant additional compounds. there is research going on about the effectiveness of grapefruit seed extract on removing / destroying bacteria in water - try having a look at that. nowadays there are large recycled bottles of clean water ( 25l) if you are staying anywhere for a period of time. the guy who you buy off, comes and replaces the bottle when required.
there are long term problems with iodine - i read the research i could find and decided against a few years ago. the other problem is that i cant stand the taste!

As # 2 says , iodine will bond to particle in the water , and the standard concentrations allow for this. Even a simple coffee filter will remove the large mass of particles which means you can use a lower concentration , at a longer time . Death (theirs, not yours) is the result of effective concentration, time and temperature. Lower concentration also reduces the taste issue , I´ve never had any problems with the taste at half standard concentration, but you will get a taste of licking battery poles if tasting it before it´s ready. See high altitude´s water page for details on concentrations & time.

But for four months , or any time staying in a urban environment , I´d just get a immersion heater and boil water in evening , and get a large glass bottle to hold it.

This link has good clear information about using iodine and chlorine. here.

I picked up some chlorine based water purifying tabs rather than iodine based (in the states) and hope to try them out, for similar 'reduce your plastic' reasons.. just arrived 2 days ago so i'll try to post later how it's going. wouldn't want to live on heavily chlorinated water for any extensive period, but i believe it's meant to be an improvement over iodine. .

95% of so-called "mineral water" is just filtered (and/or UV treated) mains water anyway, so you're not going to be any better off with the chemical pollution by buying bottles.

I used a product called Pristine (check it out at www.pristine.ca) for both my 3-month trips to India and had no problems. I would treat water from the tap according to the directions and use it for drinking as well as brushing teeth. I had two Nalgene bottles, so I always had purified water available. It's a chlorine dioxide system, so none of the iodine problems. And no plastic bottles littering the landscape.

If you use chlorine tabs, leave the top off the bottle/container for a few hours, just cover with a cloth, all the residue rises to the surface and it doesn't have that smell or taste. One thing you should look out for is algae growing in the bottle/container, due to all the lovely air and sunlight, but only if you keep re using the same.

I bought a couple of Berkey Sport, filtered water bottles to take along.
Berkey filters are supposed to be top rated and take out almost everything, even "swamp water, filthy river water or heavily chlorinated* water if necessary.

Anyone else had experiece using Berkeys?