We use 2 water filters and change them every 3-4 months. If the water source is city water, usually it is safe and chlorinated, unless you are in Flint Michigan. Many RV parks use well water, which may or may not be filtered or chorinated. The risks associated with either is contamination including sediment, bacteria, cysts, other microorganisms, chlorine, volatile organic compounds, pesticides, and bad taste. Reverse Osmosis is probably the best to eliminate contamination, but we were already set up for cartridges. Reverse osmosis is bulky and wastes water.
Camco TastePURE Water Filter
It is directly attached to the spigot, has a 100 micron sediment filter to reduce bad tastes, odors, chorine and sediment. It also has a high-flow carbon filter to help prevent the growth of fungus, bacteria and mold. We put the Camco TastePURE water filter before the water softener.
Flow-Pur 1 Micron Water Filter
After the water softener, pressure regulator, and Y valve, we have a 1-micron water filter. Bacteria range is size from 0.2-10 microns. Therefore, a 1 micron filter will remove most (99.9%) of the bacteria and cysts. There are 0.5 micron filters, and we would consider it, but our water flow is already significantly reduced. The Flow-Pro cartridges fit into the Flow-Pur canister.
After only 3 months of use, this is what the 1 micron filter looks like on the left compared to the new white one on the right.
