I bought a GE SmartWater whole hose filter housing and the hose fittings needed from a Home Depot and have used it for 11 years. Cost for the housing was about $20. All the incoming water goes through it. The filter cartridges go for from two for $9 or so to two for $13 or so. The more expensive ones are charcoal taste/chemical with some sediment filtering. The cheaper ones are strictly sediment filters. In some areas I use a Flopur Mark 8000 water softener after the filter. I use quick disconnects on everything.
Clay WA5NMR - Ex Snowbird - 1 year, Ex Full timer for 11 years - 2004 Winnebago Sightseer 35N Workhorse chassis. Honda Accord toad.