My Maytag fridge at home has a bypass plug. I have a ceramic filter and carbon filter for drinking water, works for many things in water like cysts.
In my RV the Insignia does not have a filter. I use a Camco filter, water softener to my tank then the internal carbon filter in the coach. The tank has never seen anything but filtered water; 98% of the time we are bon docking with electric service only.