On a recent ride the conversation turned to bladders and avoiding infections. It seemed that many people simply refill their Camelbak after leaving it in their bag from the previous outing.
Some bladders have antibacterial coatings, which help reduce the likelihood of a furry growth, but all bladders benefit from a little care and attention. Some advocate air-drying even using a bespoke plastic inner frame or utilising the DIY plastic golf ball solution.
If you use a lot of energy additives it seems that all bladders discolour a little but that does not necessarily mean that it is evidence of some bacterial growth but if miniature ferns are visible in the tube or the bladder it is time for a little TLC.
Removing and rinsing the bladder and tube is considered good policy and rather than allowing any bugs to develop in the mini poly-tunnel of a damp bladder on the window ledge, storage in the freezer is a better option.
You can use either proprietary tablets or some Steradent to clean the bladder and tube and an occasional replacement may be a relatively inexpensive safety measure.
And if you are unconvinced or unmotivated remember that catching lurgy is even worse than man-flu.