https://www.amazon.co.uk/Sawyer-Prod...SIN=B00FHRADQ2
Yes, becks and springs are best, but if you're heading somewhere you think the water might be dodgy (low lying areas like fields) try one of these - extremely light weight and small. Don't bother connecting it to a bottle, just use it like a straw and suck the water out of becks, large puddles or whatever.