collecting water

a cut-down old Platy to scoop, and a coffee filter / mesh fuel screen/funnel works good to filter.

Then I use a Steripen Adventurer to treat.

This may not be a good solution for you. To collect water for a filter at camp I use a Coghlan's Water Bag. 3.5oz for 2.5 gallon capacity. They are cheap and tough. A friend of mine has packed the same one for over 12 years and it hasn't leaked yet. This is likely better for group usage though.

Coghlan's is the one I've used for almost 20 years. Mine drips a little but still works. To make hanging the bag eaiser I took a 36" piece of Spectralite tent cord and tied a loop in one end. I used a small stick I picked up off the ground to make a toggle for the other end. With this rig I can hang the bag for raw water in camp. I drape my bandana over the top to keep detritus from falling into the water. It's easy to filter water right from the bag into my Dromlite. When moving camp I just turn the bag inside out and hang it on my pack to dry. The one thing that's a bother is filling. If there's no falling water available I just use my pot to dip and pour.

If I chem treated water I'd filter through my bandana while dipping and pouring.