Source Hydration
I have found the Source Hydration bladders absolutly second to none, they don't leak, don't go green and manky after five minutes and are really easy to clean, especially the "widepac". I am generally useless at cleaning my hydration bladders (much to my girlfriends annoyance) but when I do get round to it I just take the top off, give it a rinse, then wrap a tea towel around my hand and dry the inside, when I don't get round to cleaning it, it doesnt go green or manky, no matter how long I leave it (three months is my current record!).