>>2358929When I think about the hikes I've done recently, both this spring and this winter:
a) 1l (2x500ml solft flasks) for ~4-6 hours
b) 600ml (2x300ml soft flasks) for ~2-4 hours
c) 2.5l (water bladder) for ~10 hour hike I did on Monday
If I'm hiking in a location where I know I'll have access to streams I would still use a) even if it's a long 6+ hour hike.