Here’s a few tips based on what we do.  

We usually travel the last weekend in May through first week of June, so there’s usually a good bit of pollen.  If the water doesn’t look too bad, we fill 100 yards out from camp as we approach our site for the night.  We just dip the bag in the water to fill (you can rinse the output hose with filtered water before you begin collecting to clean it off).

If the water looks highly pollinated, we fill at camp, using a regular old handkerchief draped across the top to catch sediment as the water is poured from a kitchen pot.  This seems to work well with pollen.

Hang the bag high – 7 or 8 feet.  I forget what the increase is, but there’s a decent increase in water pressure for every vertical foot of travel, to help with flow rate.

We hang a rope on the same tree, vertically, with a carabiner to clip to our 6L platypus bag, hanging just above or at ground level.

If there are air bubbles, strip the tube with your fingers to pull the bubbles out.  More effective than ‘flicking’.

**Let the bag hang for 10 minutes before opening the valve – lets the sediment settle on the bottom of the bag where it will be less likely to be pulled into the filter.

***When you get to the last 2-3 inches of water in the bag, shut off the valve – this water is full of sediment and should be discarded to prolong filter life.

Following these methods, our bag works everyday on an 8 day trip, typically for lunch stops and at camp for the night/morning water needs, and lasts the whole week with only a slight decrease in flow by the end of the week.