ROYAL
RoyalHome Appliances
Back to RO Repair RO Repair · Navsari

RO purity dropped (TDS high)

Water quality has dropped or the membrane has worn out.

Why this happens

  • A worn membrane rejects less, so the TDS rises
  • Pre-filters that are overdue
  • A TDS adjuster (if fitted) set too high
  • Source water TDS has increased

Safe checks you can try

  1. Take a TDS meter reading of the purified water
  2. Compare it with the input TDS to see how much it is rejecting
  3. Change any overdue pre-filters first
  4. If the output TDS stays high, the membrane needs replacing
Good RO output is usually well below the input TDS. If it is close to the input, the membrane is done.