These PRISTINE tabs are readily available here in metro Vancouver, and relatively cheap. 50 blister packed tablets per sealed foil pouch. Treats 50 liters of water for about $8 CDN or so. But they f-ing freaking SUCK.......even new ones turn to gooey mush inside the blister packs in less than a few weeks. And who knows how long they may have been on the rack at the store....... You literally have to scrape out the tablet with a safety pin or similar. This package I bought NEW today, but i have had this problem over and over and over again with the PRISTINE brand. The tabs turn to sticky doughy GOO my KATADYN tabs are way more expensive, and about the only thing that happens to them is they turn to powder in the pack after awhile ...but they are STILL usable, all of the tablet, even in powder form. Not so with the Pristine .....you have to use two or three of the melted sticky tabs just treat one liter of water. And they dissolve SO SLOW .......over an hour. I can treat water with the KATADYN tabs one the spot - right now,done! dissolved, gone, treated! 1 out 10. Esp after being told by Pristine that i should store the tabs in a cool dry place. Seriously? do you people at Pristine even hike?