Two months ago I bought a CNOC Vessica 1 L with a 28 mm opening and took it on the GR11. This soft bottle turned out to be very practical: I used it as a "dirty water" container, onto which I screwed a Sawyer Mini filter. The filtered water then flowed into my titanium bottle. The bottle compresses very well, takes up less space than a regular water container when folded, and is exceptionally light. Once I attached it full, and later also half-filled, to my backpack by tightening a strap just below the upper rim. This worked well because the top and bottom parts are made of harder plastic. I was happy with that, because once filled it neither dangled nor banged against the backpack. The only downside I noticed was that when collecting water from a lake, the bottle, no matter what I tried, filled only to about 800 ml. Somehow it was impossible to remove the excess air without simultaneously squeezing out some of the water already collected. This is probably some specific phenomenon related to using such a soft bottle underwater. So I had to add the last 200 ml by hand, which took a bit of time. Once, while hanging it up to dry, I thought that the thin paracord could have been a few inches longer so that I could hang the bottle by threading it through itself. As it is now, the cord was simply too short to make a loop through which the folded bottle could pass. In my opinion, the 1-liter capacity is an excellent choice. I also bought a Vectox 2 L bladder, but in the end I did not take it with me because I decided that the zip closure was impractical, and the product itself seems too heavy for its purpose. On the other hand, the Vectox could easily be filled underwater. After a month of use, the plastic turned slightly yellow, but that does not bother me at all. The label stated that this results from the use of less harmful materials. Although the manufacturer does not recommend it, but does allow it, I once washed the bottle with water that had been boiled beforehand and cooled to about 60°C. Thanks to this, I managed to clean it very thoroughly.
