Depends on the area. - Whole house filter consisting of specific commodity 20" large ("big blue") filters - (NaCl) ion exchange water softener sized for the h

Depends on the area. - Whole house filter consisting of specific commodity 20" large ("big blue") filters - (NaCl) ion exchange water softener sized for the hardness -> hot and cold water to most indoor piping except kitchen cold water (for watering plants) and outside - 6 stage + UV 100 GPD RO filtration system using commodity parts. Add a permeate pump option to transfer pressure and reduce waste. There is no real cost difference in production flow rate between 5 GPD and 100 GPD except losses, minor membrane differences, and the restrictor valve. 200 GPD is tankless, so that's a minus. A US So Cal manufacturer, AMI / wateranywhere.com can ship large orders by freight for 1/3 the price a plumber will charge for a crappy wholesale system. They make RO membranes and industrial-scale desalination systems, so b2b and b2c are side markets for them. Clean out everything and run antimicrobials at least every 4 months. It's work, but having nice showers and clean water down to <1 ppm is awesome. PS: For apartment dwellers in large cities, find a reputable "water store" that has both a commercial AND retail business from the same equipment. Buy your own non-PFOS containers from the REI or some such. Sunray Waters in ATX is one example.