How do I get the water in my camelback to not taste like crap? I've left water soaking in there on a few occasions for a while, hoping to leech the bad taste out. Yet as soon as I refill it, the water tastes like plastic. Maybe it's the tubes and not the bladder? I know I can add emergen-C or powdered Gatorade, but I'm hoping to have clean water with no additives.