I think the key point in this discussion is to avoid bacteria build-up. Therefore, good practices of hygiene accordingly to the environment (e.g.: cleaning the tank regularly, cleaning the containers where the water is stored regularly, don’t allow bacteria to grown on the filtration device (Osmio. Skuma, Zero Water etc) is all safe and sound.
Recently, I had some bottled water hanging around and decided to open it up and drink it. I drank some, and then left it tucked away from sun light in my home office (read: spare room). Many times I went back to the office to work, and had completely forgotten about the water. a few weeks later, I remembered about the water, and kept on drinking, from that bottle, over the past few days. It was just fine: no smells, no bad odours or taste.