Really this post is a blatant attempt to justify to myself putting some of my oldest water bottles in the recycling and splashing out a fiver or so on a couple of new ones... But do any other cyclists have any self-made-up rules on replacing their bidons? I have one that I keep on the bedside table and have noticed that if you leave it with some water in it for a long time it gets some 'green' in there - easy to wash out and when absent mindedly swigging from, tasteless and doesn't seem to do me any harm at all - so I know the bottles aren't completely sterile. And, anyway, at least the ones I use on my bike, tend to get washed out every so often and allowed to dry properly before going in the water bottle cupboard. Even the little one that tends to be on my commuting bike week in, week out, I wash out every so often.
Nevertheless, my 'matching big ones' which I will take on long rides in summer must be going on 20 years old, and although originally white, aren't very white on the outside as the years of being jammed in and out of cages has roughed up their outers. Even my 'new' matching small ones, aren't that new anymore - probably 10 years old now.
Is this perfectly normal or disgusting and unhygienic? Even the ones that are probably old enough to vote have the recycling mark on their bases, so I guess it wouldn't be completely outrageous from a sustainability point to (recycling) bin them? Modern life is ethically very complex don't you think...?