Well, if you just have to know what TDS is, this is how you calculate it -
TDS (in mg/L) = (0.6 x adjusted TA) + [CYA] + [Na+] + [Ca2+] + [Mg2+] + [SO4 -]+ [Cl -]+ [NO3 -] + [NO2 -] + [NH4+]
You can ignore the ammonium and nitrite because those would not be found in a properly chlorinated pool. If no dry acid is used, then ignore the sulfates. Magnesium can be calculated by running the CH hardness test twice - once with R-0010 and once without then subtract the two. One can use the K-1766 to determine salt level which would be [Na+] + [Cl-].