ATI ICP-OES set reference solution is ideal for comparing against various home water tests plus hydrometer and refractometer to check wether you are obtaining correct results

ATI Reference Solution:

Salinity 35 PSU
Carbonate hardness 6,9 °dKH
Magnesium 1190 mg/l
Calcium 380 mg/l
Strontium 7,5 mg/l