Dear Sir,

We have an Aquaguard Total RO system for drinking purpose for the last 4 years. The apartment gets borewell water into the tank and when checked the TDS value was 550. When this water is routed through the RO unit the value was 50 which is good.

Now in our apartment Cauvery water is now mixed with the borewell water and the TDS value checked from the tap was 400 and after through the RO system the TDS value was 65 which the engineer said is ok.

The question is how low can this value can go as the engineer says a TDS value below 15 is not fit for drinking. Please clarify as in our apartment there is no separate tank for Cauvery water.

Thanks