I am located in South San Jose (Great Oaks Water) and have a 7 stage BRS RODI kit. The TDS going in is about 330 and drops down to 4 after the sediment, carbon blocks(2) and RO membrane. With the three DI canisters: 1- Cation 2-Anion 3- Mixed bed.
I have had to replace the Anion resin about 3...