TDS of my municipal drinking water in Delhi is 400 PPm . And I have installed RO which is supposed to have the membrane of the pore size .0001 and the TDS after the RO is now 39 ppm. Is it ok ? or I should go for the Ultra filteration membrane of the pore size .001 , which is supposed to make the water safe for drinking without reducing the TDS.

Please inform about the recommendations of the safe drinking water in regards to TDS and other matters

Thanks,
Ashok

ashokmah@gmail.com