About backpacks....... MY TWO CENTS.....

By my opinion, it sure that backpacks having few inconvenients
as to be hard to clean, the liquid is freezing into the pipe at cold times,the valve(mouth piece) is leaking sometimes depends for the brands and the models buy and also the fact that you are sweating at your back under the backpack and it turns moist and unconfortable after a hard/hot time.

By anyways ,I got 2 of thoses at home and all considered for me it`s a god gear to buy. Here `s few tips and advice I suggest you to " over pas " theses severals incovenients.....

CLEANING; Use A CAP of bleaching water wing arm`n hamer to

disinfect the tank of liquid, use water only!

AT WINTER TIMES; Put the pack under your jacket , get the pipe

out from the "under arm "or the neck

LEAKS (valves): Use BLACKBURN `s valves with the "tongue

bouton" to avoid leaks; Is the best mouth

pieces you can get on the market.

I SUGGEST; 2L Playtipus flex bottle syst./ (also in 1 L)*and bag

with a Blackburn valve this way you have a great alternative about price/quality before to buy a camelback (tm)
awsome but more costly.
Good luck!

* Cascade desing,Seatle, WA