What model of Camel Bak do you own? Have you purchased the hanger that was designed to fit inside the Camel Bak so you can hang it up to dry? What about the cleaning kit? You can purchase a kit that has the brushes that will scrub the bladder, the bite valve & the drinking tube. The kit also contains the cleansing tablets that you use. Once you run out of the tablets you can purchase more with buying a whole new kit.

Like I said in my previous response either hang it to dry or keep it in the frig. I have never had anything funky or nasty grow in any of my Camel Baks because I do this.

One last thing it is recommended that you replace the bite valve once a year. You'll have to anyway as it will wear out.