One key to keeping black moldy stuff and bacteria from growing inside your Camelbak water bladder and tubing is to dry it out between uses. First empty the bladder as completely as possible. Suck and blow all the fluid out that you can through the bite valve. Then I use an air pump that is meant for blowing up air mattresses. You just shove the pump tube into the bladder and let it run for about 15 minutes.
Next, bend a wire clothes hanger into the configuration shown, and add an elastic band. Shove the hanger into the bladder to hold it open and attach the elastic band to something. Now you can hang the Camelbak up for a day or so. This will allow any moisture the air pump missed to evaporate.
Finally, store your Camelbak in the refrigerator to make it inhospitable to any invading microorganisms. And remember to enjoy a beer after your run!