Do you think you'd trust this water purification system in rivers and streams?

I like my Pur water filter and use it on all of my backpacking trips. To keep it working properly- or for that matter any other water filter- I'd suggest you tie a bandana over the intake filter to filter out the large sediments.Pur is only made to filter impurities and not change salt water into fresh water. For the price and weight, it is an excellent water filtration system.