I use a steripen and a bandana filter, never had a problem even from somewhat questionable sources. I carry a week's worth of tablets in case something happens to the steripen but so far it's lasted over 2000 miles of hiking use with just routine battery changes.
Sent my son to the Chugach for 2 weeks with a steripen. Been using a Sawyer with good results. Be interested to hear how it worked.
