Vanessa, I only carry a small 0.5L plastic bottle for water (and only use it when really needed)... I'm more inclined to drink straight from a fast flowing burn or river.

Cheers,
Bernie

Wow! Only just seen this. I guess you must be more of a camel than me. Or I sweat and pant more. So far on this challenge I have drunk each day between 1 and 1.5 litres from the platypus plus between 4 and 8 cups from streams. And the output is infrequent and not that light. I've always been the same so it's not a problem (except the weight).