How do i clean out my camelbak?

You left more than water in it, dude. Camelbak bladders are made form a medical grade, antibacterial material, and the only way you would get funk in them is if you put Gatorade or something else in it at some point. Get your tap water nice and hot, put a couple tablespoons of baking soda into your bladder and fill with hot water. Add a small amount of antibacterial dishwashing detergent, close it up, and shake the hell out of it. Now let that sit overnight. In the morning, shake some more and rinse out with more warm tap water. If that doesn't take care of your funk, then Camelbak makes some fizzy cleaning tablets that will work wonders (you can also try denture cleaning tablets as well).

Camelback does sell cleaning supplies for the reservoirs and tubes. I know you don't want to spend any money, but unless you already have the supplies in the other answers, you're shelling out some dollars regardless.

Maybe get a metal coat hanger, straight it out as best you can. Next find a scrubber type material like the green 3M scouring pad. Cut it into 2"X1/4" pieces. Attach the middle of the strip the end of the hanger wire. Use hot water and liquid dish soap to wash the inner tube and bladder. The bladder night need a bigger pad. Rinse and wash out your camelbak after each use. Water is good, Gatorade and other drinks can go sour in a poorly cleaned bladder/tube especially if left out in sunlight. Good luck cleaning!

Yeah bleach is the best thing to use. About one part bleach to 10 parts water dilutes it the right amount, and you can either run the solution repeatedly through the tube or if you have some sort of brush you can stick inthere that would work better.

Take some bleach and mix it fifty?fifty with water fill your bladder half full and shake vigorously repeat till you get it cleaned out. Now to get rid of the chlorine taste and smell rinse with cold water then hot alternately. This will break the molecular bond of the bleach. When you don't smell bleach it is clean. I do this with all my water containers it,s the best way to clean them it is a pain in the --- but worth it.

probily umm wats its calld **** umm hold on...not windex ummmm maybe fantastic

Most likely it is algae since you only had water in it. Run hot water and soap in and work the tube to dislodge what you can. Get denture cleaning tablets or use mouthwash to do the final rinse. After this you can pop it into the freezer between uses to keep algae from regrowing if you should leave water in. Then you just have ice to cool your drink. However I agree it is worth getting some brushes. You can get small cleaning brushes from aquarium supplies or lab supply places, too. I made my own drying rack because I didn't like the one sold originally. I still have the original camel back and I have cleaned out several rounds of algae over the years. It hasn't made me sick yet.

I know you say you are cheap but your health is important & the bacteria in there is nasty. Your local bike shop has brushes & tablets that will get that cleaned up & the cost is reasonable compared to getting a new camelback &/or getting sick.