What ever works!
I go for the activated charcoal models because they do a pretty good
job of removing chlorine taste and smell.
My last pack from Lowes said 2 microns.
Whirlpool 2-Pack Whole House Water Replacement Filter
Item #: 149010 | Model #:149010
We use one under our kitchen sink on the cold water line at home
and the same thing on my hose inlet on my trailer.
Typically both get changed once a year.
I've never had a problem with low pressure thru the filter but maybe just
haven't run into dirty water.
We change the one under our kitchen sink when we notice the chlorine
taste coming back. We fill our water bottles and make coffee from
The one in the trailer get's replaced each spring whether
it needs it or not!