My tds = 0 but my rodi water is 0.35 ppm PO4 measured with Hanna checker. Does it mean my RO membrane needs to be replaced or that I need to change the DI resin ? What else to look for ? Now I understand why I can't get my PO4 down in the tank water ! The RO membrane is about 3 yrs old, filters and carbon cartridge changed every 12 months & I make about 5 gallons of water per week.
Tks for your help !
Tks for your help !