Aquamira Pro and the Colorado River

It really depends. I've had trips where the river was running clear enough just to pump straight. I use a Sweetwater. Other times, a few hours of settling was sufficient. Last month, it was as as turbid as I've ever seen it and nothing worked. I always take a paper coffee filter (better than a bandana) just in case but it was still a silty light brown. Clogged my filter after 2 liters and even my usual field cleaning couldn't get it to pump again for the rest of the hike.

If I have to depend on Colorado River water, I always take a bucket I can use to settle water in. You have to watch out for the mice if you leave it to settle overnight; I've found drowned mice a couple of times. I also take paper coffee filters (the cone melita kind, not the basket ones.) And chemicals as a backup.

There is also the alum method that many GC hikers use at the river. After my recent experience, I'll probably take this as a backup if I'm dependent on the river for more than a day.