W-B, an R.O. system features a semi-permeable membrane which "strips" the minerals off the incoming water, leaving a de-mineralized fluid to drink. This membrane is preceded by a series of filters for sediment and chlorine elimination and followed by a finishing or polishing filter for taste.
It requires about 40# of pressure to "push" water through the system which is then stored in a bladder tank. This tank holds about 1.5 gallons of water, ready for delivering to the refrig. ice maker and water in the door.
If you go to Lowes or H. Depot and check in the domestic water dept. where the filters are stocked, you can find one of these systems-they sell for about $200. One other thing, there is a waste water component to this process, generating 3-4 gallons of reject water for each gallon of product water. I dump this waste into my gray tank, but it could also be dumped into the fresh water tank since it really isn't "bad" water. I would think it also could go on the ground without polluting anything.
Since I consume a lot of water and ice, I wanted a system to allow me to make up enough ice and water on my rig without having to buy it all the time. I just can't bring myself to drink water straight from the main storage tank, even if it's filtered by one or two coarse-grained filters.
2014 Newmar Essex 4544
2007 Lexus LX470 Toad