I have got my TDS finally. and the result is not that good:
1) from the tap is 1400 ns/cm (22.3C), pH 7.8.
2) from the tap after filer (not RO) is 1344 ns/cm, pH 7.9
3) from the tap but after 3 days with shungite is 1310 ns/cm, pH 8.2
4) from the water dispenser is 155 ns/cm, pH 8.0
4)...