Hard metric values. 174. the ppm value does not exceed the standard hard and soft water filters installed to filter the water softener before login, no more than 20 ppm <.
Hardness measured at 174 ppm. Hardness up by default. And should be installed to filter water softener soft water before the system can be up to <20 ppm.
Hardness measuring 174, ppm. Hardness does not exceed the standard. There should be installed soft filter to filter before entering the system to elongated than < 20 ppm.